According to Brad Schoenfeld? Maybe. But not according to a series of better designed and executed studies, and narrative analyses. (I refer to more mainstream HIT rather than Mike's "consolidated" routines.)
Nope. The famous Colorado Experiment Arthur Jones did with Casey Viator was also proven to be a fraud. Casey was adding extra volume after hours. Dorian Yates did more Volume too. But it makes for good Books, headlines etc You try it then. There is a happy medium between Volume and Intensity. Either by themselves is shit.
Ray and Mike Mentzer were professional Bodybuilders, so I assume we are talking Strength and Hypertrophy. HIT done occasionally is beneficial. But as a base training style for Strength and Hypertrophy, it's a fraud.
Vince Gironda had a famous 8x8 program. That's on the other end of the spectrum, but like HIT, not a base long term program, due to too many Sets.
If you pretend that the video was shot recently for the sake of evaluating Ray's physique in light of current standards and protocols, he looks like an average steroid user you'd see in any gym in this country.
Think about this: when does the integrity of the movement and JOINT become compromised? Answer: at the point of Momentary Muscular Failure. How does this apply to Mike Mentzer's HIT?
Every Set should be stopped at the point of Momentary Muscular Failure (MMF), otherwise the integrity of the Movement and Joint is compromised and you're causing long term damage to your Joints etc.. Is one Set to M.M.F. enough to stimulate an adaptive response?