You're quite right.
- Evil was setting up a server with a few interesting maps (13vast,...), but now is it down ?
- In Super server, they take the bet you can vote for any map if you are bored
- ctf4ish-only is still available on uM Range server, they also got their variants. Maybe they have oa_ctf2 on some other servers but with no rotation and it's not liked enough to bring people
I recently set up ROFL Various Couscous

because I thought there was lacking variety in CTF servers.
Here is the actual map rotation :
set a1 "g_warmup 5 ; g_gametype 4; map oasago2; set nextmap vstr a2"
set a2 "g_warmup 5 ; g_gametype 4; map ctf_inyard_v3; set nextmap vstr a3"
set a3 "g_warmup 5 ; g_gametype 4; map ps9ctf; set nextmap vstr a4"
set a4 "g_warmup 5 ; g_gametype 4; map oa_ctf4ishum1; set nextmap vstr a5"
set a5 "g_warmup 20; g_gametype 9; map oasago2; set nextmap vstr a6"
set a6 "g_warmup 15; g_gametype 4; map ctf_compromise; set nextmap vstr a7"
set a7 "g_warmup 20; g_gametype 3; map wrackdm17; set nextmap vstr a8"
set a8 "g_warmup 10; g_gametype 4; map am_icyhell; set nextmap vstr a9"
set a9 "g_warmup 5; map oa_spirit3; set nextmap vstr a1"
It might change soon though, because when you play on not familiar map and when there is not a lot of people you get bored, so I may delete a few maps and put some more popular ones instead.
Unfortunately there seems to be network problems on this server (only with OA I think) and I'm not experienced enough to know where the problem comes from, but ping is usually good, so it's worth trying. You're welcome

I don't play a lot these days but I try to get there when I want to play OA.