... is NOT, i repeat, NOT the protagonist?!
What if he's instead simply an important person to the story or plotline? IE Dad or Ulysses?
We're simply presuming he's the protagonist because we've always been vault dwellers or connected to them (with the exception of Tactics and NV). But what if this isn't the case at all, and Beth is simply throwing us for a loop, and this whole "voiced protagonist/male-by-default" protagonist is a red herring?