Can H1B Extension be filed multiple times by new Employer B based on a revoked I-140 from Employer A before getting a new I-140?

My current employer A is going to revoke my H1B and I-140 immediately after I join new employer B.
I have already completed more than 6 years on H1B (my I-140 was approved 3 years ago).
While moving to the new employer B, If my H1B (transfer) approval is only for 1 year (or less)
and my new employer’s (B) PERM or I-140 is not approved (or not filed) before the extension of H1B.
How will my visa approval work in this case (with revoked employer A I-140) ?

Can my next H1B Extension by the new employer B be done with old (revoked) Employer A I-140?
– If Yes, Can the H1B Extension be filed multiple times before I get my new I-140 Approval?
– If No, Then do I need to go out of US? And what are the option of my extension and staying in US, in this scenario?