The whole Jimmy and Timmy in NASB stuff still confuses me - not their absence (Jimmy's is a little confusing, but I can certainly imagine a fair share of potential reasons), but the reaction to their absence - like, were people not paying attention to the state of Nickelodeon merchandise and crossovers at that point? And even if they were or have a reason not to be paying attention to those things, how is that a dealbreaker? "It's like if Smash didn't have Link!!" Even if we are to assume the -immies are the Link to SpongeBob's Mario (they're not, that's Lincoln currently), why would it be a big deal if Smash didn't have Link?
Seriously, it took Smash 4 games to add Little Mac and Duck Hunt, two of the most iconic characters Nintendo has ever created. 3 games to add Wario and Charizard too. Mewtwo of all characters got snubbed two times in a row. (well, more one and a half) One game to add Inkling, even with a more recent game included in the DLC cycle. 6 games to add Daisy.