No, this is all still bad writing.
I know what Word of God is, and I never said it was inherently bad, but J.K Rowling used it badly.
Word of God is supposed to be used to confirm things that may have been hinted at in the product, usually when they want to leave something ambiguous for a while and see what conclusions people come to on their own, using the hints given. Example, in KH2, Sora has the "Anti-Form" transformation out of nowhere sometimes. It isn't outright explained why this happens, but due to the appearance and mannerisms Sora takes on in this form, most assumed it had something to do with how he transformed into a Heartless in the first game. Tetsuya Nomura ended up confirming the theory in an interview.
The difference between that situation and the Dumbledore one, is that Nomura left breadcrumbs in his actual product for his audience to pick up on.
Rowling did not do this, she pulled Dumbledore's sexuality out of her butt, and never even remotely did anything to build up to it. That's really poor writing and is a negative example of the Word Of God trope.
And you're right about Obi-Wan, and that's why his sexuality wasn't discussed in interviews. Turns out his sexuality has been at least a somewhat relevant character trait of Obi-Wan's character, so that's not even a good example for you to bring up from any angle here.
So again, I ask - why did J.K Rowling even disclose Dumbledore's sexuality when she never even remotely wrote that into his character or gave it any importance?
Like I said before, it comes off as her trying to gain brownie points in the LGBT community, at the expense of immersion.