This, sadly. With that in mind we have to go off which Pokemon are most present in media outside of the games and make our guesses from there Gen 7 frontrunners are
- Decidueye - Spotlight in Pokken, Rowlet being Ash's starter
- Incineroar - Rival spot in the movie+anime, Intimidate makes him really strong in VCG
- Lycanrock - Ash's anime ace, evolution gimmick, special third form
- Mimikyu - Pikachu v3, basically manufactured to be marketable
- Zeraora/Marshadow - Late additions but both have some marketing push behind them
After that we have less likely things such as Tapu Koko or an Ultra Beast. The thing is when Gamefreak really wants to push a Pokemon, they make it blatantly obvious from the get go that you're supposed to use this Pokemon above all else, for example Greninja was Ash's starter, got a special Mega "evolution", got one of the best abilties in the game with Protean, excellent stats, everything about Greninja tells you "yes, use this one,"
But we don't really HAVE that in Gen 7, all the aftermentioned Pokemon are only so-so in battle with the exception of Mimikyu, or don't have the sheer marketing push that Greninja got. In Gen 4 it was obvious Gamefreak wanted you to love Lucario, and they tried the same thing with Zoroark and messed up, and again with Greninja, but this time it's like...there's so many potential Smash characters that it's almost like NONE of them are gonna get in and we're gonna get something ridiculous like Tangela or Slowpoke or something.