The BUFF is "squeezing the water out of the air" but that is not a supersonic shockwave.
The poor old BUFF would shake itself to death trying to go Mach 1.
BTW it is still a great picture and the only one like it that I have ever seen.
10-4. I don't believe the B-52 could go Mach + even in a dive. The airframe would come undone, I suspect.