I have never heard of such a thing, I was watching them this morrning and saw lou the roo climb in to the nest making those eggy noises most of my girls make(kind of a ticking sound) and sit on the eggs. he's acting just like a broody hen.
There are chickens that have hormonal imbalances, like humans. Maybe your roo is one of those rarities with hormonal issues.
It is the reason some hens could pass as roos(but they lay eggs), and some roos act like hens(lol, apparently going broody).
It is odd and interesting, but I don't think it is anything to worry about. Now, if he ever lays an egg, then you probably had a hen the whole time with a hormonal issue. LOL
I would be interested to see if he truly sits the eggs, and even more interested to see how he reacts with his newly hatched clutch.
If he is truly broody, see if he will sit some spare eggs for just to see what he does with the little ones. Watch him though, you don't want him to sit the eggs and maim the little ones.
Or maybe he justs needs to come out of the closet and have a good mother son talk..LOL