Ever since news for this game began in earnest I've been maintaining a google doc tracking the Pokemon that have Megas, sorted together by region and Pokedex number. If this alleged list of DLC Megas winds up being accurate, we now have...
Kanto, Johto, Hoenn
View attachment 779195
Sinnoh through Paldea
View attachment 779196
Falinks and the 4 Paldea lines are together to stay on one page in the google doc. I also included Hoopa despite no game data hinting at it due to its status as a DLC mascot making a Mega likely. In addition, Groudon and Kyogre are being counted as Mega-adjacents despite their forms being named and working a bit differently.
This leaves us with 90 Mega Evolution users and 96 Mega Evolutions in total.
Something I notice about the list of supposed DLC Megas is that there is at least one Mega for each type, which feels realistic to me, because it’s something that GF have been pretty consistent about with power-up forms. There was at least one G-Max for every type. There was/is at least one Mega for each type in XY and Z-A. ORAS’s Megas almost covered all 18, except for Electric (I wonder if something got scrapped?).
(However, the only Normal-type among the DLC Megas is Staraptor, and I’d be surprised if a Mega Staraptor didn’t shoot for Fighting/Flying given that Close Combat is like, the thing Staraptor is most known for. Unless they also make Chimecho Psychic/Normal or something lol.)