I'd definitely bring back 40s, though I'd imagine the amount of repeat opponents in those had to be high even during the game's heyday. 25s I can take or leave at this point as we've been in quite a groove with 30s lately.
Honestly the game needs some sort of global chat, even though those tend to be a wretched hive of scum and villainy in most games. This game isn't dying by any means but its base has certainly gotten more narrow and dedicated over the years. So with that said a global chat, perhaps only open to leaders and coleaders, may actually help with consolidation of some of these smaller alliances, if they are so inclined. Between all the third party chat apps, varying levels of engagement on myriad social media platforms and the company's lack of efforts behind the game's very own official forum there needs to be a universal way for all players who are so inclined to communicate. Limiting it to leaders/coleaders may keep some of the ''send ****s''-style garbage prevalent in most games' global chat down to a tolerable level as well.
Eta: Really? This forum censors ''nood''? The censorship here and in-game has gotten so heavyhanded and laughable it is beyond parody by now. The filter censors stuff that wouldn't raise an eyebrow on Nickelodeon at 3 in the afternoon. That's another post though. Just dryly amusing to me.