A non-exhaustive list of every 100k+ non-NSFW sub I've noticed that has pledged to go dark indefinitely (so far).

LAST UPDATED: 6/13/23 - 9 PM UTC, based on comments from this post: https://old.reddit.com/r/ModCoord/comments/148ks6u/indefinite_blackout_next_steps_polling_your/

r/aww (30m+)
r/videos (20m+)
r/futurology (10m+)
r/music (30m+)
r/diy (20m+)
r/techsupport (1m+)
r/chess (500k+)
r/guns (500k+)
r/china (250k+)
r/nba (5m+)
r/tumblr (1m+)
r/nasa (1m+)
r/programmerhumor (1m+)
r/apple (1m+)
r/sweden (500k+)
r/chicago (500k+)
r/asksciencefiction (500k+)
r/dndnext (500k+)
r/squaredcircle (500k+)
r/pokemongo (1m+)
r/woweconomy (100k+)
r/lotr_on_prime (250k+)
r/kotor (100k+)
r/rwby (100k+)
r/applewatch (500k+)
r/migraine (100k+)
r/me_irl (5m+)
r/cars (1m+)
r/autos (1m+)
r/reverseanimalrescue (100k+)
r/flutterdev (100k+)
r/learnjapanese (500k+)
r/abruptchaos (1m+)
r/warframe (500k+)
r/opendirectories (100k+)
r/steam (1m+)
r/animesuggest (500k+)
r/askmechanics (100k+)
r/physics (1m+)
r/askphysics (100k+)
r/restofthefuckingowl (250k+)
r/neworleans (100k+)
r/twoxchromosomes (10m+) [currently unconfirmed, will update]
r/blackmagicfuckery (1m+)
r/illustration (500k+)
r/catsareassholes (500k+)