GPTs are not trained on themselves, and what little knowledge they have of their own capabilities is limited to the discussion of it in their training set. This is a hallucination.

I might believe you if we were 'talking' directly to the model, however this is a chat box and clearly something is aware of usage questions and how to answer them. If you've been granted plugin access, enable some and ask it what plugins are enabled and how to use them, 'it' will tell you.

It's clear that it's aware that it's a chat bot, it's not clear at all that it's aware of usage questions and how to answer them. Its answer being wrong seems to be evidence that it isn't.