The situation here takes place in a private channel in KuroganeHammer's Discord server, where we (me, Kuro, Ruben, Sammi Husky, etc) talk about the game datamining.
Nov 28, back when the leaked data was floating around, Meshima managed to find the fighter param data through (I think) memory searching. We're all dying to read the new data at this point so tons of labels are added to the sheet what feels like instantly. But the first order of business with the data is figuring out who it belonged to. Since I was reversing the param file format, at this point I was able to tell that param hashes use only the lowercase letters for words. Given a big set of internal strings we had available I guessed correctly that the first hash was for "fighter_kind_mario". From then, all the characters were labeled just about instantly, with two more slots to reverse that were not in the game's strings.
Ruben gets both the new hashes quickly: "fighter_kind_packun", for Piranha Plant; and "fighter_kind_jack", for an unknown DLC character. At first we assume it's Raiden from Metal Gear so we all agree to not leak it. Keep in mind this is still > 1 week before release, we: 1) want to keep it a secret out of respect for the dev team and 2) don't want the disaster that could follow from leaking [Raiden from Metal Gear], or even simply "fighter_kind_jack". Now Kuro is able to add the attribute data for characters to his site for people to look, since we can't share the sheet due to the dlc. Since we already knew of Piranha Plant, its data was included as well. Even though we technically removed the hashes, we couldn't share the sheet due to the existence of the DLC slot.
Fun fact: jack's params were initially copied straight from Piranha Plant (the char directly above him in the list). They were modified to be mostly unique on the day 0 patch.
Move forward to Dec 5, Nintendo puts the update on their CDN so we get the fighter params for the day 0 update on day -2. This time with a param viewer I was working on, we identified quickly there was a new dlc hash for "fighter_kind_brave". Same story as last time except it took longer for us to guess who it was; Meshima figured it was most like the hero from Dragon's Quest, whose Japanese name is "brave man". When Joker gets revealed the day after, Kuro figures the most likely scenario with the first name is that Joker = fighter_kind_jack.
As far as I remember, that is actually all there is to the situation up until we see stuff start to happen yesterday. It starts with someone posted DMs in a modding server of an unknown person spreading rumors of "Jack" and "Brave" character data; I bring it up in the private channel and we assume people found out on their own. Next thing you know, Jam1garner posts a tweet showing the new hashes, and follows it up saying that it was assumed to have come from our chat. I ask for his side of the story because we're all concerned now how it got out:
Around Dec 21st, someone DM'd him asking about if he knew about "jack" and "brave" in character params. Jam says it sounds fake since he didn't know about the character params. [Aside: the person he talked to, I spoke with later to get info from about the situation, I'll just call him Person 1.] Part of what he mentions is that Vergeben knew as well. Reason he asked Jam was because there was no discussion of this in modding servers at the time. At some point as more people are talking about these character names, Sammi describes the behind-the-scenes situation about them and our channel to Jam. People from Source Gaming (PushDustin and Martin) are said to have known as well, and they all agreed to keep quiet until it more or less went public.
With this in mind we think it could be still an independent coincidence that someone else found the hashes. It was possible our chat was only mentioned since Sammi talked with Jam. That is, until we notice that in the DMs Jam got was a screenshot of Meshima's spreadsheet. The only person we know to have also seen the spreadsheet is DRAFIX, but he has no relations to the people who caused the leak. Suddenly the situation is a lot stranger.
I ask Person1 directly how he learned of the data and had a picture of the spreadsheet, he leads me to Person2. They tell me that Kuro DM'd Vergeben on his 10 year old gamefaqs account (aerodrome2). Sounded very fake at first, but this person also provided screenshots of the private channel, screenshots of the chat history where Ruben reversed the names. It may be worth noting, Ruben and Sammi both are using their most recent profile pictures in the screenshots, which puts it at Dec 22 earliest, which would be later than the leaks started happening.
Now in the chat, we bring up the possibility that someone hacked into Kuro's accounts. There's 3 main points that support it:
1) Discord can have multiple instances of the same person being logged in, which would allow someone to spy or grab the spreadsheet link.
2) At the time, his accounts all used the same password and 2FA was turned off.
3) His Gamefaqs account's DMs had been all wiped back to 2010.
However, the part that doesn't make sense to me is there's no obvious motivation for hacking into his accounts. We never shared that we knew who the DLC names were, except possibly through Piranha Plant's attributes.
There were 3 relevant names brought up surrounding how the data got to Source Gaming, and where the screenshots came from. However I don't wish to pursue the matter any longer. There are some takeaways from my perspective:
1) This could have been done in minutes by anyone who knew even 1 fighter_kind name. Fighter names were labeled way ahead of time with the exception of these two dlc chars, but it seems no one except for us (and competitive players) cares about datamining that until spoilers are involved. It could have also been solved without hijacking someone's account information.
2) People seem to make a big deal out of the labels from that file, don't treat it like they appeared there out of nowhere please. Meshima had most of the labels already added to his spreadsheet by himself with some assistance from us, I did most of the work with reversing hashes on that file. Maybe just give a shoutout or something idk, it's not like I needed to reverse the format and make all the programs you're using :( (@ mizumi tbh, I don't dislike you but this kind of stuff is unpleasant)
3) Despite Martin knowing way ahead of time I'm extremely disappointed in SG's video on the subject. They had like two weeks to prepare at least something with accurate writing, but it's just all around inaccurate except for which patches had the data.
4) Smash 4 did the exact same thing with their fighter_param file with DLC, except they didn't hash their enums like they do in this game. I'm super disappointed people didn't pick up on that.