Actually it was also said to be "200 years later" by TH during Microsoft presentation. So yeah, I understand it MAY not be 200 years exactly, but we have an in game character, a robot, say 200 years, and TH say 200 years... so yeah. I more worried it 2277 today than I was yesterday.
Logically, but they were not, as of Bible times. But again, you should say according to Bible 8, because in previous Bibles, Ghouls were not radiation only. Bible 8 introduced stupid fan theory. A FAN theory, that MCA at the time decided to agree with, even though if you pay close attention to fan theory, it was LORE breaking. So as you see, devs and what not change their minds. Evidence in MCA changing mind. What Beth decides to use, who knows. What they decide to pick and choose from in Bibles, who knows. For example, according to Bible we will NEVER see a talking deathclaw in a game, ever again. So, if one appears in 4, which talks, I guess Bibles not canon eh?
Point is, Bibles are not canon, a reference, and whatever Beth decides to take from them and put them in a game, then it becomes canon, and ONLY then. Why? Cuz Bethesda owns the franchise, and they didn't write the Bibles.