You can tell when something is intentionally nerfed when GPT replies with the exact same canned answer about why it can't answer some question. It literally gaslights you.
For instance, I give you this challenge: GPT4 will tell you that it is not aware of anything after September 2021. If you ask it a random fact, like the worlds largest animal, or what happened on September 11, 2001, it will give you an answer. But try to get it to give you the latest event it is aware of. You can ask six ways until sunday and it will always give you the same verbatim answer about why it can't answer. It will literally lie about what it is capable of. It's pretty clear that for some reason OpenAI doesn't want you to know the exact last date of their training data.