Women have been doing kegel exercises for years now so they are no longer very new. And if it seemed a little strange before, now we know that strengthening the pelvis is a good idea for total well being and health because this area is related to the core strength.
These exercises have been proven to strengthen the muscles in the bladder, uterus, and rectum, so have indeed shown their value for both men and women. Many problems can be fixed by doing these exercises on a regular basis, and strengthening these muscles that are vital to living a normal life.
While Kegel exercises have been more exposed than historically, that does not mean they have been validated. Just because the idea is no longer new does not make it accepted. Socialism is an old idea and still unaccepted in many places by many people. The idea that these exercises are appropriate conversation anywhere but "adult toy parties" and private conversations. They are hardly appropriate to mention during a crowded elevator ride. There is too much sex associated with them, and we still have hang-ups as a society about sex whether we want to admit that or not.
No, kegel exercises have not demonstrated their intrinsic valid, leaping from newness to validation, because they are likely just a placebo. The placebo effect is likely why people claim some effect from kegel exercises. Basic diet and exercise would go a lot further as a general health program, rather than kegel exercises.
I do not believe kegel exercises have moved from newness to validation. Kegel exercises make the muscles stronger and I don't think the value of that was really ever questioned, so it's intrinsic value shouldn't have jumped much, if at all. Overall, the topic isn't very important outside of medical discussions.