Ask any doctor. Inability or unwillingness to err... perform and infertility are TWO utterly different categories. One behavioral. The other physical.
I don't buy infertility due to damaged comb unless there is a huge fever/infection, systemic involvement.
His testes aren't in the thing, they aren't going to be harmed if it freezes or is dubbed.
While from a production standpoint the temporary point is the same - roo isn't servicing anyone, they're pretty darn different.
Many many things like this are said, and believed by poultry old timers. Unfortunately these are the same guys who put it in the pot the moment they realize the extent of the frostbite, death being permanent infertility.
Hard to prove otherwise.
Many things like that are said about other species and other old wives tales. That it's been said for a hundred years really does not make it true.
As most who have had one survive and let it recover have pointed out - they're quite fertile.
We've been sort of superstitious and uninformed in our pasts, including misinformation handed from generation to generation.
It's a way to get good info, it's also a way to get bad.