Software suites like Houdini, which is something of an industry standard in VFX and gamedev can potentially leverage ML techniques. AFAIK the folks who make Houdini have talked in the past about using ML to improve their terrain heightmap modelling, improving the quality of the erosion etc...
The real value add with using procedural tools to automate creating parts of large worlds (eroded terrain, placement of foliage according to rules) is that it frees up artist time to focus on hand crafting individual locations and detail into the map.
There is an interesting talk from Ubisoft which talks about how they leverage tools for building their large worlds https://www.youtube.com/watch?v=NfizT369g60 (slides: https://ubm-twvideo01.s3.amazonaws.com/o1/vault/gdc2018/pres...)