>>42145507None. Zero. I'll be surprised if they even do an enhanced edition at all.
1. They can't really do much with the region being a ton of simple paths, unless they overdo it and add not-Ireland, or have some cataclysm or something scramble the map.
2. The cut dex can't be messed with, either. AT BEST, we'll get the currently-locked Pokemon like the other Kanto starters and Melmetal's Gmax form. It's very unlikely they'd add to or change the national dex too much in any way that isn't compatible with the original versions.
3. TPC and GF are tightening the noose on pushing things out much quicker than they used to, I almost guarantee they're working on gen 9 and maybe 10 right now.
My guess, they'll toss out a few gyms, add in the missing ones from the lore (ha), add an NPC that lets you pick a Kanto starter, slap in another cutscene or two that should've been in the original, and then go full force on advertising something new to the Wild Area, like a new den color.