That doesn't matter, honestly. The situation is not the same if you change the gender and sexuality of the people involved. A joke about two men in a humorously sexual/romantic light is not the same as a joke about a man and a woman in a humorously sexual/romantic light.
Like... an announcement tweet for a youtube video does not warrant this level of analysis, but I do want to explain why it's an unavoidable truth that the context is different.
There are stories revolving about "guy and girl accidentally obtain a baby! shenanigans!", to such a point there's a lot of tropes around it. There's been enough premises along those lines, you have a whole host of stories on the concept across media.
For queer people, that's not the same. There are very, very few stories about two men raising a baby, and even fewer we could look to for actual queer representation or as something more than a one-off vaguely homophobic joke or beyond the Very Special Episode-mold. That is thankfully changing in the new millennium, but there's a lot of ground to make up.
When you tell the same story for the millionth time about a heterosexual couple, it's par the course and there's plenty of variety to be had. Want a serious story? Want a sad one? Want a happy ending? You can probably find multiple examples of those. For a queer audience, though, they are most of the time just the butt of the joke, and its frustrating to see it happen again.
It's the same thing with queer folks being tired of romances about them that almost inevitably end in tragedy and death. Variety is wanted. For young queer people, it's actually in desperately short supply. Most stories about queer people are either humorous at their expense or they revolve around the Tragedy Of Gayness (see: Brokeback Mountain, good movie, but man not exactly a happy one).
I hope that explains why making the joke about a heterosexual couple is not the same as making it for a homosexual one. That's what Zoey meant about it being baiting and frustrating. It's just another example of having the type of story you really want advertised to you only for it to be a gag.