I have received a written offer from a US university (University A) for a tenure track position which I signed and returned after agreeing on all the negotiating terms. However, I have not heard back from the University (Provost's office) regarding the official background check and onboarding process for over a month now. The department chair is usually responsive, and we had several email conversations about and around my starting date this August. Having said all this, I am still waiting to hear from University A more specifically provost's office, and from my end, tensions are mounting as I have already rejected an offer from another university (University B) and stopped interviewing at other places. The University B offer that I rejected worked differently and completed the background check before sending out the written offer, which was pretty quick.
Now that I am left with nothing but to wait and hear from University A, I am wondering if there is a chance that University A might rescind its offer at this stage.
Update: The university did not rescind the offer. I was able to join as AP however, I did not have the onboarding started as late as Aug 10, 2023. In the meantime, I had to relocate (~350 miles) at my own expense with my family with this uncertainty. In the process, the Department Chair was helpful in assuring me with my concerns and questions.