There’s a lot of potential options. Gen V remakes are next on the main series remake list. Let’s Go and Legends were both sort-of-mainline-ish games that would be about right for a sequel. I’m betting there’s still more DLC for SV. And wasn’t there a rumour about another Detective Pikachu movie?
I think most companies are actively against public suggestions. If they do something like what you suggest, they may be liable for paying you for that idea. But if they’re already working on something like your suggestion, and then you suggest it, then they either have to pay you for an idea they already had, or risk you taking them to court and having to spend time and lawyer money on proving they owe you nothing.
They were pretty direct remakes with a few new bugs and a controversial art style. I was never a big DPP fan and the remakes failed to change my mind.
I do think any future remakes will be different though, i vaguely remember a story about ILCA who made BDSP and I don’t think they exist in the same form as they did when developing the game.