H1B Visa Stamping during Transfer to another Employer

I have been working with Employer A and Client A since 3 Years. Had to return to India in August 2020 due to Family Emergency.
After a lot of struggle got Expedited Appointment on Jan 14(Finger printing completed pending with consular appointment), but Employer A told me that company is in merger process and I cannot attend Interview until 2 months.
So I postponed my Appointment to Jan 29 and will apply for H1B transfer Premium to Employer B on Jan18(LCA submitted on Jan 11), Client will be same.
Given the timeline, I may or maynot receive Employer B’s 797 copy. Can you please let me know if it is ok I can carry Employer A’s 797 copy which is valid until December 2021 and get stamping.
Employer B will be providing me Receipt number, Employer Letter and all documentation required.