Geno's such a weird character to me, because while I think he's likely just as much as any character, every time I see evidence towards him thrown around, I don't see evidence, I see assumptions.
Cacomallow:
It's fake, but today's post didn't change that, because it's 4chan, anyone can come in and say anything anonymously. The fact that it's a video leak that's been up for almost an entire year now when the Nintendo Copyright bots have attacked videos for less, that's not a good look for ol Caco. You'd think, with how many times it's been uploaded and reuploaded that it'd have been killed, but, no, it hasn't. Some people will say that they won't take it down because it'd be suspicious, but they forget that it's bots, bots don't give a **** about that, and the fact that Cacomallow wasn't killed on sight by the bots the minute it was uploaded is VERY telling.
The missing Mii Costume:
Is not evidence, because we've already seen how sporadic these are. Heihachi got dropped on our heads when no one expected it, and we're still missing others from Smash 4 like Rathalos Armor and Lloyd. A lack of info is not a good enough reason to assume, especially since we know that they're still bringing most, if not all, of the old costumes back. Could Geno be upgraded to a full character? Yes, but he could also become a Premium Costume with his theme, never assume this is a 'hint' unless we get another Square character, they bring back the Chocobo hat, but not him.
Gamespot's 'LEAK':
I'm not even going to spend time on this. The video was filmed in June, and Nintendo pulled out of E3 back in March. People seriously are out here trying to claim that Gamespot had access to Nintendo's E3 plans when they pulled out in early March, and they just happened to leak Geno of all things and nothing else, especially odd since there isn't a single credible insider who knows who the next Fighter is currently, let alone do we even know if we're getting one soon.
Mario Tournament:
This is my own speculation but, if we don't get Geno before this, and we don't hear anything about him coming via a trailer drop during this thing, he's as good as dead to me. With how much they're hyping up this Tournament, you'd figure that they would want ALL the Mario content to be either in the game for it, or to be shown off, but if November comes and goes, and assuming Challenger Pack 7 isn't Geno, and Challenger Pack 8 comes sometime in 2021 and it's not hinted to be him during this time, then he's taken a devastating blow in my eyes.