Please Sakurai-San, say it ain't so!! There's still so many characters that haven't even been in Smash yet, we can't let this be the last one. :(
Basically, according to NintendoLife, Masahiro Sakurai notes that Super Smash Bros. Ultimate could be the last one in the series, taking into account the effects Smash has had on his health and personal life.
I know Sakurai has those things to look out for, but I don't want this to be the last Smash Bros.