Ironically enough, catering the franchise to children could end up being the saving grace for turn-based battles. Turn-based battle systems in general have a lower difficulty threshold, not having to worry about skill ceilings like timing, combo's, etc like you do with real-time action. If Game Freak does try a real-time battle system, you can bet it will be heavily watered down for the sake of the children. However, even as I say this, I heavily disagree with this cultural norm, because lots of children grow up playing complex games, and even surpass adults with things like obscure information retention and reaction timing. Our culture tends to coddle children, but they are much more capable than people tend to believe.

Regardless of these hypotheticals, turn-based battling is one of the most important core principles of a traditional(mainline) Pokemon RPG. Mainline games have already removed other Role-Playing mechanics like HM's, so once you change the battle system, you might as well call it something else, like an Action-Adventure.

I've thought about ways to refresh the 4-move limit, and my personal change would be committing to 4 moves on the fly.

At the start of each battle your Pokemon have their full list of learned moves in a separate column, and with each turn can freely choose any move. However, each choice locks in that move for the rest of the battle, maxing out at 4 moves. So basically, you're retroactively choosing your Pokemon's 4-move set on the fly with each battle.

This would open up a Pokemon's moveset if you keep them in your team for specific moves like False Swipe, Hypnosis, etc. It would also give competitive battles a lot of room for spontaneity and unpredictability, like forcing your opponent to choose certain moves defensively to limit their Pokemon's offensive move pools.