When he came from Tri Armstrong was quite bulky; some even claim that when he returned from illness he was a changed person, with lower upper body bulk and thereofre a reduced weight. Could it simply be that after "years" of doing other things including MTBing etc. he bulked up again? I am not so sure about the need for such upper body strength either.
My hor comment was an 'off the cuff' remark. I'm not suggesting you need massive upper body strength, but it would be required for an hour record especially if you consider that when trying to hold the pursuiters line at 50kph on a 250m track you are probably going from straight to banking to straight every 5 seconds. Also the hour would require conventional drops and not tri-bars.
I know things have changed a lot since my day, and maybe the relative importance of weight training is less and more bike specific methods are used, but I would imagine that the 5 'S's (speed, strength, stamina, suppleness and pSycology) are still important aspects of any distance track training programme