I agree, there is a lot of speculation and no way to know what's really going on. I think it's safe to say he'll probably bounce back around at some point whether it's mental, physical, health related or any combination of these factors.
As far as pegging him as a once every year kind of guy, didn't he run 28:3X as a frosh in a low key debut at Oregon? That and his frosh cross season (consistently running at or above Derrick and Shadrack Kiptoo the entire season) makes me think he's got something more than what comes around every year.
Runners ebb and flow, the reason it's so silly to say that so and so owns so and so is that they are rarely both at their best for a long period of time. Someone is often dealing with sickness, injury, mental ruts/issues or are in the heaving training cycle dumps. The mental ruts can be the toughest (ask Webb and Ritz) to overcome.
Derrick has been very impressive, out of that class has been the most durable AND the most consistent high level performer for sure. This doesn't mean that Luke and Fernandez can't come back around during college or as pros. Hell I've been around long enough to say that Fout could be the one setting the standard years from now.
Lets hope they all enjoy success.