I've betatested dozens of MMOGs over the course of 10 odd years and not one has ever closed it's doors for 2 entire months literally 4-5 months before release and DIDN'T also push the game back. A recent one that did (in fact the ONLY other one that has AFAIK was Pirates of the Burning Sea, and that was recently pushed back.)
I don't know, it's fishy. Most MMOGs close down the servers for a few hours while they bring the latest beta client online. If it's a big change, it might take a few days. But a few months? Theres something they aren't telling us.