My only real problem with these maps in the map pool is that there is no feedback to whether someone is downloading or if it crashed when a game has been found, and the waiting time can be quite long (seems to be over a minute sometimes in my experience). That could be fixed if people were forced to download all the maps before being able to queue. If people have problems downloading the maps the best we can do is provide a different way than the client to download them. But others shouldn't get dragged down with them just because they have bad internet.
In custom games you have to download maps before joining, or at least there's a message that someone doesn't have the map, so they get kicked.
Ladder shouldn't be excluded from having the best maps we have to offer. I think it would be a shame not to use these maps.
Apart from that it would be good to have an easy way to see how much space your maps and mods are taking up (maybe in the "manage installed maps" window as a small info?), because some of these maps are really pretty big (around 150MB) and I can imagine it piling up over time.