GameCube controller now compatible with Switch

[PAOerfulone]

If Smash 5 was in development, we'd know about it by now. They usually announce something is huge as a new Smash Bros. game WELL ahead of time to build up as much hype and anticipation as possible (remember the Smash Dojo?)

Brawl was announced in 2005, revealed at E3 2006, released in 2008. 
Smash 4 was announced at E3 2011, revealed at E3 2013, released in 2014.

If they announced Smash 5 now, I wouldn't expect it until 2020/2021.