@FunkOff In order to have procedural generation of "fair" asymmetric maps I think we would need much more advanced AI, similar to what DeepMind did with StarCraft II. If there were highly-skilled AIs that could duel it out on maps thousands of times, it would become possible to programmatically test what kind of asymmetric distributions are fair vs. unfair. An AI map-making agent could learn from those experiments how to develop "fair" asymmetric maps.
Before anyone attempts to make a mapgen that creates fair asymmetric maps, maybe we should create a few by hand? Perhaps we need a map-making tournament for people to create some "fair" 1v1 or 2v2 maps that have significant amounts of asymmetry? I'm talking about significantly more asymmetry than just "the map is symmetrical but there is an island in the middle with kind of a bean shape."
If the financial incentive was big enough, people might participate. I personally would like to see "fair" asymmetrical maps become part of the ladder pool. I think it looks nice when maps aren't always mirrored and probably makes for more interesting games. Since the ladder pool is already divided by rating, we could just remove the asymmetrical maps from the 1700+ pool (where small differences might affect game outcomes in a significant way).
if anyone with less skill complained, we could just blame the victim. If someone said "I have 1340 rating and I lost a ladder match on Asymmetrical River Map, get rid of asymmetrical maps from the ladder pool" we could say "I watched the replay and you made these 3 obvious embarrassing mistakes, git good noob"