>>715493331
It was definitely the push the Kutthroats gave him back in 2014/15 and that push coming to fruition in 2018. But the actual reason also relates to EAD's stance on characters; if they didn't create them, they won't touch them. Obviously this isn't an ironclad rule, but it's a consistent one. Notice you'll see a new baby each Mario Kart game up to MK8 and even a powerup or an alternate take on a character (Cat Mario and Pink Gold Peach) but you won't see someone like say, K. Rool or even Mona or Captain Syrup? That's why. Those are characters made from spin-offs of the Mario brand and they generally stay segregated from the main Mario cast. When they had to increase the roster size starting with the late N64/Gamecube era, they started using Diddy Kong, Donkey Kong from Rare's games, Wario, Waluigi, Daisy and so on. They CAN use any character they see fit, but they'll usually bring in a powerup or create a character (PGP, Baby Rosalina). Funky Kong was a huge surprise at the DKVine back in 2008 alongside Sluggers having more Kongs and the Kremlings/K. Rool. The former being an EAD game, so you're less likely to see a character like Funky in their games, but they went and did it.

>>715495618
The mandate wasn't really a mandate, but a guideline. But it was present and NSMB had a huge hand in establishing it. I believe that one post from NeoGAF saying that said people behind the mandate also kept Waluigi segregated to the spin-offs. Within another decade, do not be surprised if Waluigi pops up in the next Wonder/NSMB/Mario platformer, or even gets a game of his own. All jokes aside, he is popular and has genuine fans.

Paper Mario may still be fucked though, TTYD and SMRPG be damned.

>>715408094
This, Tanabe's shit ruined DK, Metroid and Paper Mario. He deserves all the ire thrown at him.