I don't think they've been waiting for approval since 2019. It just took them longer than they expected to perfect it. Japanese people aren't really known for being liars, I doubt he's making it up.
We are talking about Japan here, not America or Europe. I don't think you realize how forward-thinking and liberal they are when it comes to regenerative medicine. In six months they will know if it works or not, the trial won't last more than a year before they seek approval. Approval will take less than a year probably, so that's under 2 years. It won't take any time at all for them to begin offering it on a limited basis. It will only take years if you are waiting for it to become more widely available, and for the price to fall. If you have half a mil in the bank I bet you can get this done in 2023, if not sooner. If you're a broke college student then yeah it's going to take ten years before you can afford it so just get a hair transplant.