If anything Smash-related is to be announced in tomorrow's Direct, I'm placing my bets on Smash 64 and Melee being added to the Nintendo Switch Online Expansion Pack. Since Sakurai and his team with Bandai Namco are currently working on Kirby Air Riders, you can't expect them to work on anything Smash Bros., new or Switch 2 Edition, so putting 64 and Melee on NSO would be the easiest option since they don't have to do anything with it.