This is interesting idea but it not necessary "fixes" all the problems: first of all you still need to somehow select those official maps and while you wrote "all the best ones" in the very next sentence you mentioned "popular maps" as well.. so I guess it's going to turn into yet another flame war about which map to include.
It will make much more sense to choose the best of the best maps instead of deleting others maps. Now everyone will have to actually convince us all (or to convince Lewin/TDL/...) that their map is good enough and/or popular enough. Someone who has a map in the Remake right now, will feel like someoen smacked him in the face if we delete his map. If we delete all maps then start adding them from scratch, it is a bit different.
There is also another problem with this solution - completely "locking" official maps is a bit counterproductive if you want to introduce file transfers because this feature was introduced to make it easier to spread new maps among other things, this also includes any new version of existing map made by the original author of the map. What if he/she wants to try out new version ? Back to "old" method ? Renaming it ? Sure it works but testing is limited to people willing to help and if the new version is simply better most people would be out of luck.
But also other people might steal official maps and make their own versions of them. There is no way to distinguish an average random destroying a map, and the true map author. Do you really want people to end up with incompatible, different versions of the official maps? With your way of thinking, if I update Frozen Waters, it depends only on players whether they will like it and will spread it through the entire community. And, which is a worse thing, it's very possible that someone will make an easier version of the map, with 2132143214214 iron and same amount of gold and coal and etc., and will spread it, like a virus, practically removing my version from the game. Do you want that to happen? I'm going to kill such people with my bare hands. I don't spend time on my map only to see some brainless guy replace my mountains which took a fair bit of time to make, with some ugly mountains of his own, only because he needs more resources.
As a side note, since this would mean that people installing the game for the first time won't have immediate "access" to all the maps - I didn't tested the file transfer yet but I assume it's just "download" button, if it's not then disregard this part completely - people new to the game might be unwillingly installing a lot of (possibly popular) junk, perhaps adding some metadata like screen shoots, etc. available before download would help mitigate the "clutter" ? Or perhaps maps should not be written to disk unless you actually start game on the map ?
Lewin will make sure only relevant map files can be downloaded, since this way you could download even viruses as well... I believe he even already made it so you only download the actual map files, and nothing more than that. Also, last sentence is a neat suggestion, but doesn't replace my idea in my opinion. And thanks for giving feedback instead of another trollpost!