I'm kind of curious to get everyone's thoughts on this.
In the last 2 waves of DLC, a spot was saved for a character from an upcoming game that would release later that year. In Smash for Wii U/3DS, this character was
. In the first Fighter's Pass, this character was
.
Do you guys think we'll close out the second Fighter's Pass with a character from a 2021 release? Personally, I don't see why not. Nintendo obviously likes the free publicity that comes with Smash (although, how much Smash benefited the sales of Fates or Three Houses is unknown), while I imagine Sakurai likes the opportunity to make Smash more up to date with modern releases. It's one of the few patterns that we've seen thus far that has gotten a direct confirmation of "Yes, this is what we were going for when including these characters".
Obviously, who that character would be is currently a massive shot in the dark. So far, the only 2021 Nintendo releases we know about are 3D World (which is already represented in Smash) and Monster Hunter Rise. However, we do know that BotW 2 exists and could be a 2021 release, while Kirby Fighters seemed to foreshadow another potential 2021 release in the form of the 3D Kirby game referenced in its code.