TL;DR - Yes, change it.
Long version:
We've had 4 of the same maps in rotation for quite a while. Even with changed flags, experienced players know every move and counter-move that each team could take. Also, most maps are nearly impossible to win by MEC side. Winning Jalalabad with MEC is a miracle, because of the ease with which US can capture first 4 flags.
I would love to have all maps mixed in to play with them. It would give opportunity for people to play with all kinds of vehicles and try their skills on maps that they haven't played before. This is still possible on the big server, but it's not that fun, if you can muster maybe 10 people at the time.
You should also consider impacts of changing maps on kits that people use. 9/10 you will use AT kit on the big server, because of the number of vehicles. Our city maps are primarily INFANTRY maps, because flags are close together and there aren't many vehicles to destroy. Therefore you don't need AT with you all the time to stop tanks mowing your squad down. Of course snipers will love some maps, especially the Chinese ones with lots of foliage to hide them. That being said having all maps would "unlock" the EU and Chinese kits for use on regular basis and they have some cool weapons.
So considering maps into rotation, you should probably mix in INFANTRY and VEHICLE maps between those. Infantry maps don't have to be city maps necessarily, but 32-player versions of some maps have flags close enough to provide fun without too much running (considering most of the time the server doesn't have 32 players anyway) and limit the number of vehicles. Then have a 64-player map with all vehicles (and running) involved. But I don't think every map must be included, for example Highway Tampa and Zatar Wetlands are pretty much the same thing, so maybe choose 1.
And to top it off, it's not like we can't try the change for a few trial weeks or a month and if it turns out to be a disaster, change it back. You won't know until you try it.
P.S. Machete your signature image is creepy as hell.