That's not an easy task to do - we would probably need to remake most of the minimaps completely from scratch, which would be an enormous amount of work - probably it would be somewhat 80-100 hours of work. ALso quite a lot of people like to explore a map. I personally would not want to see everything of a new map int he skirmish menu. I just want to see what the map looks like, so not everyone would be happy about that.
Even though I understand where the idea comes from and it would be helpful in your games, I don't think that it will be made in the near future.
A more possible solution would be to add map overviews to the wiki, but even that would be a lot of work, but probably a lot less (probably less than 10 hours?).
Or as a final solution (which is not 100% practical), one of you could always open the map in the worldbuilder - you don't have to change anything, but by opening it, you can always see where everything is and you can decide afterwards, but I can understand that this is not really practical.