Bamco sticking with just Pac-Man is just so confusing.
Like, with how much they've helped with this game and with both Smash 4 games, you would think they'd get least one more. So incredibly strange to me. Considering the options we have left, I'd narrow it down to:
Tales of: Lloyd is the obvious pick here given the fondness the Tales community has for Symphonia, but I also wouldn't sleep on Yuri: Dude's mega popular, and the rerelease of Vesperia only helped with that.
Soulcalibur: I will admit I have next to no knowledge of this series, so I can't comment on it much. I feel odds for it are decent, but if Tekken couldn't make it, I'm not sure about this one.
Dark Souls: Probably Tales' biggest competition. Barely anyone talks about it in the Smash community as well, which is kind of surprising to me. I wouldn't at all be surprised if we got a Chosen Undead Mii skin at the very least somewhere in this pass. It could very easily make it's way in as a promotional pick as well, assuming DS 2&3 Switch ports are in the works.
Taiko no Tatsujin: Don-chan.
Despite having yet to play the games, I'd love to include Klanoa on this list...However, to my knowledge, his series is kinda dead and he doesn't have massive fan backing like Banjo did, so IDK if Namco would specifically go with him.