Idk. Have you tried? (I mean, assuming the maps are original design and not taken from another game or something)
Yes, they design is original. The only thing is that i also use assets from the game, which you know, they do that too to keep the aesthetic consistent.
And no, why would they take something i did? I don't have any professional background, and they don't like freelancers. What options do i have, DM a GM and be like "Hey i made this map, want to put it in?" I don't think things are as easy as that.