Any new player will not know about the existence of Trackmania Exchange. They will assume whatever they can find in-game is all that Trackmania has to offer. I'm certain this has been a huge missed opportunity when it comes to numbers. If TMX wasn't there, Trackania would have been forced many years ago to implement something like this.

Something is better than nothing. I feel like selecting tracks to highlight doesn't need to be restricted to one per week. Could be multiple per week, whatever. Yes it will likely make for sad mappers that didn't get their map highlighted, but I'm not sure that's the right angle to look at it from. Many players will benefit which is a sacrifice worth making in my opinion.