I definitely wouldn't like that, and I doubt that many other people would. For starters, people like myself have spent MASSIVE amounts of time gathering and training Pokémon with special events moves and desirable IV spreads, and since RNG on the 3DS will be practically impossible, people would be lose those Pokémon and be stuck with SOFT RESETTING as their only way of getting even semi-desirable IVs - and the special event moves would be lost forever. The only way I'd be willing to let cross-compatibility cease to exist would be for GameFreak to destroy the IV system altogether and to have all Pokémon of the same species be equal (with the exception of their Natures and how they're IV trained).
I'm a dedicated RNGer. I've RNGed in every generation since Emerald version to BW2. I have boxes full of RNGed legendaries, shinies, and competitively ready pokemon. I have spend countless hours learning RNG and grinding for them so I know your pain.
But if I were to pose a question to Masuda, I would ask, do you seriously want us to go this far just to be on par with other players? How long will it take for the pokemon company to realize that almost everyone knows the inner mechanics of IVs and EVs. I want him to actually realize that the entire pokemon community is aware of these details. So rather than make EVs/IVs these hidden details not referenced in-game, just reveal them in-game already, give them a pokemon terminology. Let everyone be on the same page, rather than only veterans know about IVs/EVs. That being said, there would be no need for RNG, if they made items that allow us to modify IVs. Make these items purchasable. So people like me or you don't have to go to such extremes just to be on par with other players competitively. And those that feel that IVs give pokemon personality, to them I say that's what descriptions like "Alert to sounds" are for, but why do they have to affect IVs? Can't we just have unique descriptions without affecting IVs, I mean there's natures already.
To get to the point, add customizable IVs using easily available items that don't affect personality. Change the IV system, don't change personalities and people would be happy. Allow cross-compatibility for all those people that want to keep their first starter in RSE or DPPt, but could you please allow us to change IVs with items so if our Fennekin has terrible IVs, we don't have to breed it with a ditto to get one with better IVs and lose it's sentimental value as our first pokemon. Even if cross-compatibility is not there, at least we are not bound to bad IVs and can change them at will without affecting personality.