I don't see why they would have, so I'm going to go ahead and say that no, they haven't. Registering your IP was not implemented to be able to track if people share accounts. It was implemented when a hacker was remote-hacking people (accessing people's accounts by sending them a packet when they're online or something like that). This wasn't possible if the account was also tied to a specific IP. Spoiler PS. Kudos to me for the suggestion way back when. F4
As Tobi said, there is no change to the account sharing policy. The Register IP function has now been implemented into the server's code and no longer needs to be done by the player. It is done automatically for them.