I could find no specific literature article on the subject. Some religions like Taoism strongly suggest that preserving the vital fluid is conducive to longevity.
Is sex-restriction, practiced withouth CR, really favourable to longevity? Males? Females? Scientific literature?
Of course if we practice CR or downregulate mTOR anyhow, sex-restriction is a natural consequence because we exit the proliferation & growth mode, the set of genetic expressions favourable to mating, proliferation, growth to the expense of repair & manteinance.
It may be even be that we have the usual U-shaped curve, extremes of restriction (without CR) and indulgence are harmful, whereas being moderate and following the instinct without deliberate stimulation is all right.