Also Rotoms were not included on that list. Here's form differences I didn't include (Does not include Gender or Alolan, I have those covered)
  -Pikachu (Cosplay, hats)
  -Pichu (Spiky-Ear)
  -Unown
  -Castform
  -Deoxys
  -Burmy & Wormadam
  -Cherrim (Sunny/Overcast)
  -Rotom
  -Giratina
  -Shaymin
  -Arceus (Multitype)
  -Darmanitan (Zen Mode)
  -Deerling & Sawabuck (Seasons)
  -Tornadus, Thundurus & Landorus (Therian Forms)
  -Kyurem (Fusions)
  -Keldeo
  -Meloetta
  -Genesect (Drives)
  -Greninja (Ash-Greninja)
  -Vivillon (Patterns)
  -Flabébé, Floette, & Florges (Colours + AZ's special one)
  -Furfrou (furstyles)
  -Aegislash
  -Pumpkaboo & Gourgeist (Sizes)
  -Zygarde (5 forms based on completion)
  -Hoopa
  -Wishiwashi
  -Silvally (types)
  -Minior (colours)
  -Necrozma (Fusions)
  -Magearns (Original colours)
  -Alcreme (63 colours and decoration combos)
  -Zacian & Zamazenta