www.cacklehatchery.com/product/golden-comet/
Here's Cackle Hatchery's page listing Golden Comets. You can see the roosters are not the same as the ones you just found.
OP's rooster, and the ones you found, are not Red Sexlink roosters. The whole point of sexlinks is to be able to sex them by color.
So if Golden Comets are one kind of Red Sexlink, then OP's rooster and the ones you found are not Golden Comets (or ISA Browns, or Red Stars, or any of the other names used when selling such birds.) For the photo on Feathersite, I think the person who sent in that photo was wrong about the chicken's breed.
I get the basics of sex linking but idk about this specifically and I'm definitely not trying to be a smart-aleck, but the consensus on these threads is that these cockerels may be "second-generation red sexlink X red sexlink?" Hatchery oops!? One every now and then? What do you think?
2nd generation from parents who were themselves Golden Comets, yes that is a possibility. In the second generation, either gender can get either coloring, or the coloring of either original parent breed, or a few more as the genes show up in different combination. If someone breeds two Rhode Island Reds, the chicks are Rhode Island Reds. So a person may think that breeding two Golden Comets will give more Golden Comets, even though it does not.
Hatchery oops, only if the hatchery had a red hen in their breeding flock along with the white hens and the red roosters. If they want to sell sexlinks, they should be checking to make sure that does not happen. This is not a simple sexing error among the chicks they hatch & sell, because a male like this should never appear at all if their breeding flock is set up right.
One every now and then, not unless it's a hen genetically but has a hormone problem that causes it to look & act like a rooster. That can happen, but it is quite rare.