I don't see how he could do this considering we host our own servers, also taking into account third party rental servers.
I doubt this is Badspot. He would have to update Blockland (heavens forbid) and remove multiplayer client features that have no strain at all on his machines, as far as I know. It seems very pointless, we're all (relatively) happy with the Blockland we have and he knows it. If he makes another Blockland, if he's bothered, it will simply be Blockland 2. You can revert to the older versions of Blockland and the multiplayer will work because it's hosted by you, the player.
Badspot isn't an idiot and he knows the amount of work people like Pecon, Tezuni, Sylvanor, Greek2me and countless other modelers, programmers, game-mode creaters, mega-builders etc. have put into the game. If he would actually do this, he would announce it on the forums ahead of time rather than waste time on a server. This circles back to my original argument that he would simply make another blockland and leave the old one alone for all the old folk to play around with.
EDIT: Perhaps the only strain would be the registering system and our beautiful forum. Other than that, I really don't know.
TL;DR: This defies all common sense.