Looks like you are thinking too much and getting worried, you are safe, relax.
Question 1: If my previous h1b is revoked will it effect i94 date (08/2019) ?
Ans: If your employer B revokes H1, it would automatically invalidates your last I-94 with 08/2019(but hold on, you will be fine, read rest of the answers below)
Question 2: Is my stay unlawful? I have moved to employer C when i have valid approved H1B petition
Ans: You stay is lawful if you have the Employer C filed H1 petition receipt notice is in hand and its either pending OR approved.
Question 3: If employer C petition is denied, what are my options? I am I eligible for cap excempt?
Ans: You are eligible for cap exempt if someone files a new H1 if the Employer C’s petition is denied.
Thanks for your response. 1. i94 date on CBP portal is 07/2018 and i94 date on H1B petition is till 08/2019. So if my employer revokes my i94 date is 07/2018 or the last day of my notice period with employer B?
Employer C had filed H1B petition and status changed to “Notice explaining USCIS actions was mailed”.
Before my current status change to Denied, can I transfer my H1B to other employer and stay in US just to make sure of more Approval chances?