Normal male penguins do this all the time, caring for the egg while the female goes to eat.
What the zoo isn’t saying is that the “gay” penguins don’t actually have sex, nor attempt to procreate, because even the animals aren’t stupid enough to think that would work.
Male and female penguins in the wild actually group together for a lot of reasons, the primary one being to keep from freezing in the winter.
I remember when I first experienced gerbils with babies. As you said, the father would sit on the newborns while mama ate and sometimes rested. These male penguins are doing the same thing. They don’t try to mate; they are just roommates.
This is a hit piece from the media to try to go to lengths to show us how animals are gay, too. It’s a choice, people. It’s behavioral. Behaviors are CHOICES. We may all have tendencies of one kind or another, but we have choices that we make every day on which behaviors we will act upon. I am not a tidy, organized person by my nature, but I try to discipline myself to keep things somewhat orderly most of the time.