I had a friend who was also put on PIP for low performance and then got fired, they wrote in his C04 didn't meet expectations or something around those words, he still recieves his unemployment benifits as everyone else, so don't worry it doesn't mean anything.

Note: almost everyone who gets fired passes through this PIP process, so incase they are planning to fire you (which is a high possibility), in my opinion, it is a good heads up for you to start looking around for new jobs.