What is the most likely scenario, is that Nost admins that are waiting for lawsuits and whatnots from Blizzard, are given a deal and make that request to shut down all private servers to not be SUED and to make compensations on the verdicts so they get off easier.
This said, knowing the community, of course Nostalrius does as asked by the Blizzard as they do know that the community knows better than to obey a request from long dead ghost which they are as they are in hell called Blizzard's lawsuits. At the same time profiting from the notice themselves and maybe getting into the heaven.