To be fair, privacy policies are worthless. They could have a squeaky clean privacy policy and still collect data on you illegally. I did request a copy of all my data under the relevant consumer law for where I live, and it looked like they weren't collecting anything they shouldn't^. That's still not a guarantee, but it's better than nothing.

^ They did still have a copy of all my old assistant threads, including deleted ones, but a mate who works there says that was just a bug with the system and should have been fixed. This was about a year ago.