As a brand spanking new player coming over from WWIIOL I must say I'm extremely disappointed in the current status of the AvA arena. This is exactly the style of gameplay that I'm looking for, and yet there's nobody on the server. Nuts.
As for the maps being stale, there's a solution for that which would only involve switching out the available equipment, rather than a whole new map.
For example, take your "Battle of Britain" map. Sure, you can use it to play out the battle of Britain with Spits and Hurries vs 109s, 110's and some bombers. But here's some other scenarios you could play:
Operation sealion: Same equipment as BoB, but add an attacking german naval force. Allow ground vehicles to spawn once the Germans have captured a Brit airfield.
Dieppe: '42 equipment (Folk Wolfes and Spits), and the BRITS have an attacking naval force (with tanks).
Normandy: '44 equipment (Americans AND Brits vs Germans), and the Allies have an attacking Naval force. Allies may attack with tanks, the Germans can only have them once the Allies capture an airfield on the mainland.
All 3 of these scenarios can be added using the existing BoB map.
Appologies if this has already been mentioned or done before. Like I said, I'm new here...
As for the original poster, no, the AvA arena is NOT redundant because there are some people like myself who like historical matchups. Spit V vs Spit V is just as boring as P51 vs P51. 109 vs Spit is the more interesting setup, IMHO.