The hypertrophy induced would be very, very minimal, and the likelihood of someone using that for hypertrophy having the knowledge of the needed calorie requirements for hypertrophy to actually give lasting results, is very low.
But, he said he's not aiming for hypertrophy, but I still just think it's a bad idea, unless your goal is specifically to be better at long sets of pushups, because that's all it's really good for - doesn't recruit nearly enough typeIIa/b fibers (those with the good potential for hypertrophy - pushups are far more typeI), too hard to get a good cardio/lung session in, not really that efficient of a calorie burning exercise, and, while not an isolation movement, isn't nearly as compound as many other comparable exercises which could be used instead.
Further, I'll be the first to admit I never much got the "maintaining" approach to training, like Dazer says:
"What it is aiming for is just maintaining general upper body fitness, which that workout does very well I felt from experience."
Dazer:
So, are you meaning that you're where you want to be, both aesthetically and functionality-wise, and simpy want to maintain? If so, may I ask 'where' you are to get an idea of the condition you're simply trying to maintain and not improve? Further, why would it be relevant to simply "maintain" the fitness of your pecs/triceps? (*fitness here describing nothing more than the muscular endurance of said muscles)