The human body is perfectly capable of recycling sperm without ejaculating. Nocturnal emissions (Such a stupid euphemism. They're not night farts and we're not in Victorian England, just call it wet dreams or sleep jizz and be done with it.) are far more likely hormone linked than masturbation linked, the correlation between masturbation freq and wet dreams is very weak, weaker even than the nofappers claims about it's correlation with T levels. What little correlation it does have is probably just due to the secondary effect masturbation habits can have on hormones and would disappear if you measured and controlled for hormonal changes. It is already known that for people prone to wet dreams masturbating more will likely have little effect and vice versa.

But it's understandable that you'd think that though, even NPR managed to find a quack MD to claim that abstinence will make that happen.

Same for the prostate health, the one study that suggested a health benefit was weak, and later studies have failed for find any correlation within normal populations.