Be lucky you even got a PIP. I met with my manager every week for 6 months because we were focused on contract updates. Not once was there even a remotely close discussion about poor performance. I was let go for being below expectations in early December, the day before I was supposed to get my review. I never saw it, so I have no idea what I did wrong. I was never on a PIP in nearly 30 yrs, never had a convo that can be construed as a warning. It just came out of the blue. You're never supposed to be surprised by your review and if you are, that's indicative of a terrible manager or management that changed your rating because they want to get rid of you. So, yes PIP is an obvious warning and something you don't want, ever. But, it may not matter anyway. Take it from me.