Alright, time for a tin foil hat theory, although I'm not sure if I should call it that.
So, remember when the Steve presentation was announced for October 3rd? Nintendo made another Tweet saying there will be no additional Fighter reveals. However, they haven't made such a Tweet today. And also, The Game Awards 2020 is a big event, just like E3. When was the last time we had a double reveal? E3 2019. That being said, there's a chance that we may see two Fighters instead of one.
But at the same time, I am still feeling anxious because Jonesy is a character who will be universally hated among the entire gaming community, and I feel like since Fortnite Season 5 is using portals to go to other dimensions, what if the Smash trailer is Jonesy teleporting to Smash? Fortnite in Smash shouldn't be possible outside of Miis, as we already just got Steve two months ago, and he and Jonesy can both craft buildings by mining materials, which would just make the latter a rip off of the former. I am much more comfortable seeing Jonesy as a Mii Gunner as that does him more than enough justice. Steve is also the first character to represent modern gaming and Fortnite is too recent, having only just came out three years ago.
That said, LRG still hasn't disclosed the release of Shantae (GBC), so I wonder...
P.S.: Don't think of me as trying to raise my expectations and hopes. I'm not. I'm just presenting a theory and I am still anxious about this whole ordeal, and I am trying to calm myself down.