iPod mini was the first with the capacitive touch wheel with integrated buttons. It came out in 2004 and patents usually only last 20 years, so it should be fine to use the tech as long as you don’t use an apple logo, or any of the advancements they made in 2005 or later.
Fewer than 700 concurrent players means that they probably weren’t making enough money to keep the servers running, let alone bug fixes, or even development.
The only example I can think of where that has happened would be Ryan Reynolds & Deadpool. Iirc he kinda just stole the costume after the 1st movie wrapped filming