Well if I'm wrong I'm wrong, but, unless they get included, typically the trajectory of a character who gets brought up due to some fleeting recency is to fade once someone newer and shinier comes along.
Y'know, like Prince Fluff, Suzie, Magolor, Ghirahim, Groose, Demise, Fawful, Nabbit, Wonder Red, Fleming, Zoroark, Victini, Genesect, Deoxys, Micaiah, Caeda, Viridi, Hades, Dillon (who is now back in the news), Anthony Higgs, Elma, Tethu, Claus, Kumatora, probably Funky, inevitably Celica, Midna, Linkle, Toon Zelda, Tetra, Gooey, Black Knight, Tharja, Hector, Mallo, Hoenn Trainer, Kalos Trainer, Johto Trainer, Fiora, Lana, Isa, Matthew, Magnus, Captain Rainbow, Monita, Hawlucha, Zael, every gen 7 currently requested once gen 8 comes, and most third-parties who supported Nintendo in the last half-year. Among others.
But y'know, if I'm wrong I'm wrong. Exceptions are out there.
Call me once Marx actually starts recurring more than once every quarter century past remakes and cameos...