When a player has 3 characters per server you're saying they should say farewell on each server forum?
/me votes for the usual reasons... it's understandable. You don't want the general forum area (where new, old and potential players look first) looking like everyone's unsubbing.
Whether they actually are or not is a different matter.
as a side note, there won't be a real injection of interest until MxO has something other than stamp-collecting. Players don't want "A story", they want "their story". Unless there is a way to increase your power or be able to do things you couldn't before, it's all just stamp collecting. Who wants to spend a week grinding though a bunch of missions, to get an item that may give you 1 or 2 points advantage... as long as you use it at exactly the right time, in the right circumstances.
Of course any change such as a level cap raise will be a temporary reprieve from such stagnation, and I don't presume to tell the devs how to run the game. There is a fundamental issue however, where the top of the in-game achievement tree has been still for so long that the majority have hit that ceiling and will immediately hit the next ceiling unless lots of content is added. Massive, epic boss types (like the Bathory warf corrupted) only server to alienate a small population. Single player content needs to be increased to bring the population up and then the rewards need to be proportionate to the challenge. The patchers headgear is not worth the trouble in many people's opinion while the ninja gear is a lot easier to get and the rewads are massive.
Just some thoughts... I've had plenty of time to chew them over.