Help regarding h1b Transfer

[palad1s]

I have recently changed my employer and the new employer has filed my h1b transfer and an RFE was issued recently for proof of employee-employer relationship. While my new employer is working on getting the documentation sent out to the USCIS, I have recieved a call from my previous client asking me to come back, if I need to go back to my previous client, I can only go through my previous employer. I am not sure if my previous employer has revoked my h1b, so in this case, will my previous employer has to apply for h1 again or can he use the same h1 (if he hasnt revoked it yet).

Also does my previous employer has to wait till my current h1 is processed and approved to file an h1 (if he has revoked it earlier)?