To this day, June 11th, 2013 remains as one of the best days of my life. Seeing my favorite video game character of all time join one of the biggest video game crossover franchises was the dream of dreams for me so you'd be crazy to think that I wouldn't want the blue bomber to make a return.
That being said, I hoping that they give us a better variety of colors/alts, music from Mega Man 7-10 (especially Mega Man 9), and a more fleshed out moveset for the upcoming Smash for Switch because even though he is extremely fun to play as, he has a lot of flawed moves whether the case may be too much end lag, bad hitboxes, or even some moves that can potentially do a lot more harm than good to you.
I also wouldn't be surprised at all if he were to get a few new moves. A lot of returning characters received some new changes to their moveset and Mega Man has 100+ abilities as source material to work with.
While I won't say that he's a quote on quote "shoo-in", I'm optimistic that he'll be back, and he'll be back better than ever.
Fingers X!