I am on H1b with current employer A. H1B and I 94 is valid till Aug 31st 2021. Extension is already in progress. Now, I have a new employer (say B) who is willing to file for H1B transfer under premium. But the issue is my I-140 approval with current employer was approved on Feb 21st 2021 and it would be only after Aug 21st 2021, I can move to a new employer and still be able to retain the priority date. New employer would be filing for H1 transfer under premium in another 7 days. Can I join new employer after Aug 31st 2021 like in Sep 1st week, by then my current I-94 would have expired but H1B transfer is already initiated? I am worried about the possible few days gap between I94 expiry and H1B transfer approval with new employer.
There should be no issue as you have both, a timely filed extension of status and change of employer petition before the expiry of your current I94. You can start with new employer once your I140 complete 180 days.
Thank you for the quick reply.