Right, I had forgotten about these examples, but now that you’ve mentioned them, it’s true that attempting to use a blood pact at the only reason Dumbledore can’t face Grindelwald seems to be covering up the relationship more than anything else.
From another angle, though, I think I’ll wait for the next film to truly make up my mind about the matter. There is one reason behind that: Crimes of Grindelwald is set in 1927. Back then, homosexuality was considered a taboo and was illegal, so I wouldn’t be surprised if characters -even Dumbledore- did what they could to hide it. I’m not sure what the politics relating to wizardry were on the matter, but in the UK, homosexuality wasn’t legalised until the late 60s. If we draw a parallel between the world of muggles and the world of wizards, then I’m not too surprised at the line “they were like brothers”. That reasoning will only stand if it’s actually addressed in the third movie, though -as you said, with Dumbledore coming to terms with the fact that he has to fight Grindelwald.
To sum it up, I think I’ll give them a chance to make up for it in the third movie (by revealing the actual romantic/sexual nature of their relationship and addressing the reasons why Dumbledore might not have said anything more in the second movie). Though I agree that this
Would have been much better.
As for J.K. Rowling herself, as I said, I’m not up to date on the subject. But I do not agree with what she promoted in her recent book.