He has had, a few times in the past, a practice room F or G, and I've heard him blast out painfully uncontrolled E's while warming up, but he's never had a gig-ready E or even Eb.
I suppose it's possible that every player could develop the ability to play "high," if they tried a methodology well-suited to them, and/or studied with a teacher well-suited to them, and/or happened to play equipment particularly well-suited to them. But many players will probably not luck into the right combination of factors at random.
I will say this: To every one of you who has responded by claiming that every player would be able to play "high" if they did what you do -- you're wrong. Every methodology/technique/pedagogy/school-of-thought/philosophy (of playing the trumpet) has its failures. Every one. If you can't accept this, you're blinding yourself to reality.
The amazing potential of the Internet is demonstrated in the fact that we now, as trumpet players, can be exposed to so many different methodologies, whereas in the past what we were exposed to was a function of geography. When I was a young brass-player in Colorado and New Mexico, I'd never heard of Reinhardt or Caruso, Claude Gordon had edited my copy of Arban's, and Jerome Callet made outrageous claims about his instruments in the back of ITG journals and DownBeat magazine (and apparently published method books on the side). I never heard of Maggio until I read "Learn to play the Maggio way!" at the bottom of an old big-band chart in Walla Walla, WA, and I had no clue what that might mean until... the Internet.
The challenge now is to try to filter the dreck out and evaluate what actually might have promise. And the odds for a trumpet player struggling with playing "high" now may be no better than they ever were, because now the problem is too much conflicting information, as opposed to only one regional school of thought.
In closing, all you lucky players who are developing awesome upper registers, from G above high C up to double C, must not live near me. And I don't doubt you -- I'm just thankful that you're apparently not in my zip code. I'm well aware of my place in the trumpet food-chain, and it isn't at the apex. But I'm doing okay with a solid, end-of-the-second-set F above high C. But I sure wish I could stumble upon that Magic Method.