Oracle Principal DevOps Engineer interview questions

Applied for a Senior DevOps Engineer position. Talked to recruiter then had a screening call with the hiring manager. Got a take-home assignment to complete which was relatively easy, finished it in a few hours and then had to do a presentation to their team on it. Followed up with 2 technical interviews and behavioral interview. They ended up giving me a very generous offer, I interviewed for a Senior role but got an offer for Principal based on my skills and feedback. The equity was much more than I asked for while they matched the salary ask. I accepted their verbal offer but found out the week after that the offer had been rejected by Oracle management which was very disappointing given the time and effort spent on the interview process. No reason was given as to why it wasn't approved but I'm guessing it's related to the hiring freeze they have (and the fact they wanted to give me a Principal role). Would really love to know why or if I could have done something differently. Having the offer rugpulled on me like that seems unprofessional from such a large company but then again, what can I do about it?