Yeah, I don't think they can do it for the main games because it wouldn't work for PvP, but it was certainly better than what we have now. I agree that it wasn't feasible for this game, but I wish they took some lessons forward in terms of speeding things up (I was more referring to text boxes speed and other design considerations).
Farming out the DP remakes was a good idea from a resources standpoint, but the result that we got was incredibly disappointing to me. I liked that Gen, and while FR/LG and HG/SS are among my favorite Pokemon games ever (and ORAS did a great job revamping Hoenn but was super duper bogged down in new Pokemon bullshit), but the DP remakes are bland and added very little. But if it meant they could put their focus more on innovating, then I agree.
I highly doubt we'll see what you're saying happen. The flagship series still sells about twice as much what Legends did, and there's no way they're changing the cash cow until it proves the milk doesn't flow. I do think there's a decent chance that Legends gets to be its own series that tries to innovate more, and I'd be ecstatic just to see that. I love your proposal, it's just not feasible.