COS from H4 to H1B, impact of H1B revoke from previous employer

Currently working on Valid H4EAD valid till Dec’2022.
Have approved H1B i797B and never be on H1B status(not yet utilize for single day).

Currently working for Emp. A on H4EAD(valid till Dec-2022) and got approved i-797B. But not willing to continue employment with them.

Emp. B has filled my Changes of Status(COS) from H4 to H1B(i797A) with future date i.e. 15-Dec-2021.

In case, if I resigned from Emp. A while my COS is in process with Emp. B, is there any possibility that Emp. A can withdraw my H1B petition?

If they withdraw/revoke my i797B, can I still consider my as cap exempted? Based on that, Emp. B can file my COS from H4 to H1B (i797A).

@Kumar / @Kalpesh_Dalwadi - Can you help me understand this situation please.

Legally, H1B sponsoring employer has to withdraw H1B once the H1B employee leaves. So yes they will/should withdraw H1B petition once you leave.

In your case because you have never worked for the H1B sponsoring employer on H1B status, technically your H1B is considered never activated. USCIS can deny cap-exempt on basis of above. That said, there are cases where H1B beneficiaries were approved for cap-exempt H1B by another employer even if they never worked for the original sponsoring employer so it just depends on the adjudicating officer.

Thank a ton dear Kalpesh.