Well if you put on your tinfoil hat - maybe someone wants to track who's viewing which patents, which they can't do when it's encrypted. You're right, it doesn't make any sense to do this, so there must be an ulterior motive.
They'd have that data already, so could just share it directly.
I'm just playing Devil's advocate here.
No, a third-party attacker can just look at size/timing of packets to figure out which page is being viewed, especially given it's among a limited and static corpus.
If third party tracking (for malicious intent or otherwise) is the main reason behind the change, why not do it how everyone else does?
It stands to reason they just don't want to deal with SSL termination anymore, for whatever reason. Though, at least in my eyes, that's a solved problem too.