Changing Employer on H1B when I539 (H4 dependent extension) is pending with USCIS

[poojabeawar]

My current employer (A) H1B is approved until April 2020, but the H4 extension application (I539 for my wife and Kid) is still pending with USCIS. Their I94 is already expired, as per law, their I539 extension was already filled before I94 expiry. Now, mine H1b has been transferred with employer B, but the H4 extension(I539) was not filled together. And my dependents are planning to go back to India in November(next) month. So, my question is should we go ahead with the process of H4 extension because I have switched employer? Or, my family can stay until next month with the pending I539 application from my current employer A.