On the one hand, yes, this is true. On the other hand, it shouldn't take decoding doublespeak to know that a "performance improvement plan" has nothing to do with improving performance, and is just a box-checking CYA exercise to make a paper trail for firing someone.
And the way in which people learn this obnoxious bit of doublespeak is by having plenty of readily findable sources telling them "this is a box-checking exercise for firing you, do not believe any HR information claiming otherwise".