Apparently she saved another plot twist for the series finale by telling Harry Potter fans that Dumbledore is gay...

I wouldn't have guessed it. Is it relevant to the story? Not really.

So I wonder why she outed him? Was it to show that there can be "cool" gay people? I guess. I think most people already know that, just like most people know that there can be "cool" and "uncool" everything else. Race, religion, sex, etc...