If they did make one it'd be a great chance to fix some of the older problems they had with the hoeonn region. Such as the imbalance of pokemon in some places e.g. way too many tentacool in the water. 3 extra generations will allow for more water pokemon to inhabit the water. and how some sections of the game didn't get enough focus (the safari was a half-arsed job and was pretty crappy overall, though the bases were cool, they didn't serve much practical purpose and most of the bases were too small to put anything more than a couple of tables and a poster) Plus I felt like the desert wasn't... used enough. It would've been nice if it had a rock climb HM required bit that could also be explored later in the game like how the player can return to meteor falls and fight the elite four again.
Plus, they could add some smaller region for the player to go to (like the sevii islands in fr/lg). This'd give them a chance to include some snowy biomes and if they place it towards the end of the game it'd give the player a break from all the water.
There's a lot of good ideas and nice concept places in hoenn too (volcano, abandoned ship, rainy-tall-grass biome area), which would make for some nice sights, considering that gen 6 has a focus on beauty.
Game Freak seem to have been working quite a bit harder on pokemon now as opposed to Black/White, too, which definitely suggests if they did remake hoenn, something to the level of detail above could be created and done well.
So overall, I think a remake would definitely be good.