>>53275362LGPE WASN'T an exact port of RGB, FRLG or Yellow (too much got changed, including changing the MC's to not fuck the original timeline) and was in fact made because Game Freak couldn't legitimately get away with releasing on 3DS any longer and that's also ignoring BW/BW2's reception was seriously impacted by Nintendo advertising away the adult market that buys in alongside the kids by shilling 3DS since before BW launched in the west. And then they went and released a remake in the new Gen for the new system, just like every other past system saw a remake from GBA. And with Switch and Pokemon's sales on it remaining strong, there's no great hurry to get the brand off it an onto the new system (It can do as it traditionally did and curated the final years of a system alone, while Nintendo prepare the kiddy version of the new console, to then launch Pokémon on).
It's all moot anyway, Nintendo need to announce the new console and odds are it won't come this side of 2023, given they know how anticipated TotK is and how viable it will be to help drive holiday sales (especially if its reception is even half of what BptW's was).