I did. I asked my recruiter upfront, what's the payband. He provided me paybands for both E4 and E5 (base + bonus + equity ranges). He also told me I would be considered E5 ideally, but if the interview performance is not up to that levek, I might get E4. He said FB doesn't try to low-ball people but they want to ensure they set us up for success. Awesome recruiter!
All roles. It's a range for a given position that the comp team has ideally set. Some companies are strict with that range (can only negotiate within the range) while others are flexible around it (can go higher if presented with competing offer and you had a great interview performance, otherwise you get something within that range by default).