You see t here is huge difference between what can be theoretically done, and what can be done with profit. Nobody will invest a penny into projects that do not return profit. I think i give quite good estimation of work that needs to be done for your idea. 150 thousands of maps is order of magnitude more that total number of maps created until today (and that is optimistic evaluation). Your idea while technically doable, will never give any profit. Doing same stuff proceduraly will give you game like no mans sky. I am uncertain if procedural generation of huge areas is less or more work than old fashioned making maps. Yes one can make some procedural map quite easy, but then look “no mans sky” making fun procedurally generated map is a whole new story.
So for your idea:
is it technically doable? My answer is i think so, no big obstacles here
can it be used to deliver fun game? And my answer is no, cost of making fun environment outweighs potential income of one or more orders of magnitude.
What if it’s a big multiplayer open (round)world with a castle on an isolated islan that only opens once/month for pvp battles with an interesting story ? And you can explore every inch of that world with medieval houses where players can live and do things.