I never understood why but there's a lot of westerners who have this "vision" of what they think Smash is supposed to be. Like, a lot of the requests end up being a platforming character or a cartoonish character because they "fit" the game more. I never got this because this is the same game with Solid Snake in it so it doesn't make any sense.
Those platformer characters are fine, but the issue is that people are wanting characters that WOULDN'T FIT IN like: Doomguy or Scorpion (Mortal Kombat), Sora from Kingdom Hearts (Which will be a BIG mistake because Disney is STRICT with their properties, which results in adding Goku from Dragon Ball to SSB), Kratos from God of War, any Team Fortress 2 character, and i recall that some people went as far as to wanting Baldi from Baldi's Basics in Education and Learning to be in SSB. These types of Fan-Demands is deemed to ruin the series just as bad as adding Goku into the series, because the western audience majorly demand Western gaming characters, and they meant the ones that came from M-rated American games or something. If i am correct, some people even wanted Cringe-inducing content like Fortnite and Minecraft (Not intended to insult anyone) to be represented in Super Smash Bros.
I just wish Sakurai stops overworking himself and think about other franchises rhat need a revival. I mean, if Smash Ultimate receives its TRUE FINAL addition, Sakurai can work on other projects that need a revival. As of now, not only i am cirrently supporting Arle's inclusion in Smash Bros, i was hoping for Nintendo to Finally REVIVE Panel de Pon, and since almost nobody has any interest in the franchise, Nintendo has to convince the fans that to promote Panel de Pon to the West in its original state, Nintendo announces that Lip, the main protagonist of the franchise whose games were hijacked by the Yoshi characters and the Pokémon, is COMING to Super Smash Bros as the Ultimate Final Fighter, and since she is a Nintendo Character, she will be free just like Piranha Plant.
SSBU started with Piranha Plant as the first DLC Fighter, and if we are lucky, Arle is one of the paid DLC fighters in between, and after Smash Ultimate receives its last Paid DLC fighter, Sakurai announces that he will revive a Nintendo Franchise, which i hope will be Panel de Pon, and if it is Panel de Pon, Sakurai openly announces that Smash Ultimate's Last Paid DLC Fighter isn't really the Last fighter, and then announces that Lip FINALLY Blossoms into Super Smash Bros as the Ultimate Conclusion, in regards to Panel de Pon's revival, and if that happens, Arle and Lip can FINALLY Fight in a Nintendo vs. SEGA Duel just like Mario and Sonic used to do, but Arle and Lip are the ones continuing that Rival Legacy.
I think they're referring to little-known characters that never got their games officially exported, or ones that aren't that present anymore.
But really though, there's still plenty of mainstream third parties still, so of course they'll focus on those first. They can't have obscure characters for every DLC slot, otherwise there wouldn't be much buyers left.
Besides, there aren't many big-name Japanese companies left that haven't had one of their characters in here yet without resorting to Westward.
The Obscure Nintendo fighters can just be Free DLC updates like that they suddenly got announced out of nowhere, just like the trend back in SSB4.