Never
Why are people saying no? Is this a joke?
Never
Yeah, I think E4 sounds about right. E5 at FB starts at about 1 to 1.5 years as L5.
Yes, E4 is possible. Facebook likes high performers that get promoted quicker than average at other FANG companies. Make sure you tell the recruiter that you got promoted to L5 within a year and would only be interested in proceeding with the interview loop if you're being considered for E4.
Definitely no