You know if our bodies really need to ejaculate they will just do it in a wet dream no? Or will that cause prostate cancer too?
Ejaculation was not found to be correlated with increased risk of prostate cancer,
low frequency of ejaculation was. I think the point about the prostate cancer has more implications beyond prostate cancer. It and other findings suggest that not ejaculating has multiple negative effects. It's not like someone is perfectly healthy and then suddenly gets prostate cancer. There's a long, often unseen, buildup of ill health over time that eventually develops into full blown prostate cancer. Greater frequency of ejaculation has also been found to have other benefits in both humans and animals, but that's a story for another thread topic.
You can point to Dr. Bass re: limiting ejaculation, but I can point to Aajonus Vonderplanitz, who is pro-frequent-ejaculation (as are the results of multiple studies). Pointing to gurus is regarded as a logical fallacy called arguing from authority and doesn't prove anything.
I don't think it's about ejaculation directly.
We agree and I think the other hypothesized factor you mentioned--stress--is more likely a real exacerbating factor in hair loss than ejaculation, though I don't think there's enough evidence to term it the main underlying cause of chronic male pattern hair loss, as there could be one or more factors underlying the stress, such as the combined effects of the whole modern diet and lifestyle (in addition to other factors like genetic susceptibility to both chronic stress and hair loss).