Yes, those were interesting days! Very exciting results with OW also and very illuminating.
Exposure to extreme cold is certainly very beneficial for certain athletes in sports at specific times. As Pakewi has pointed out, most of the research has been conducted in Poland originally, (though the initial experiments and tests were started in Japan I believe).
Again as Pakewi has also said, considering Cryo from a peripheral standpoint is myopic.
There are many applications in the medical health domain psychological areas.
Also blanket application of Cryotherapy is foolish, it is (as with most things) best applied selectively and with cognizance of the athletes long and short term recovery.
Every year or so, some physiotherapy journal or other publishes a paper showing no effect on vasodilation or vasoconstriction and then comes to the conclusion that exposure to cryo is of no benefit in sport … myopic at best.