I know it's probably nothing but I'm surprised not more of you are talking about this.
We did talk about it.
There's really not too much to discuss, since we know those are official images. Either it's a coincidence or it's not, who knows.
Now, this Tails image we've been studying seems
awfully coincidental with the fact that Sonic is one of the characters sticking outside his border. Also, if BOTH 3rd parties got multiple playable characters, that would explain why Mega Man's AT is something as humdrum as Elec Man.
That said, as Leonyx pointed out, they use the same artwork in the new video and in addition to Pikachu, Kirby, and Sonic sticking out of their frames, Olimar is also sticking out. Would they really add Louie, Alf, or a series enemy when Pikmin is so small of a series and doesn't vary much in characters? Who can say.