Actually, the reason it got attention is that it could potentially lead into Chun-Li or a Tales rep being added. A popular theory is that FP2 consists entirely or partially of characters who were planned but didn't make it. ARMS would've gotten a fighter had it come sooner, we know Steve's been in development since around the SSBU base game planning, and Sephiroth is rumored to have been the result of dealing for Cloud for Wii U, 3DS, and Ultimate. Plus, it's just pragmatic to tie up loose end with some extra deals floating around.
Of course, nothing says they need to come back, and even if it's true the rumor could ultimately lead to nowhere.