Yes, things like original email and Nickname are some of those questions because after they change the public might have no way of figuring it out. Notice the support tech asked for those informations and when provided with it he said that he couldn’t verify ownership, this means OP reported wrong information for the identifying questions.

I’m not saying the service is great, asking him to access an email he claims to have lost access is dumb, but everything after that the tech support person did his best, and I don’t think he should have disabled 2FA, since it could be a social engineering attack.