I saw that too. It is a facebook group and the moderator of it and groups for pretty much all DCU (and I think he has a group for each of the arrowverse shows) clearly has connections somewhere and loves to constant girl vauge hints for attention.
He usually isn’t that specific and honestly am a little surprised. He could be right but he also told everyone when Swamp Thing’s cancellation leaked “don’t worry it is fine” and well… we all know how that worked out. He also corrected someone incorrectly on where Swamp Thing was filmed and didn’t respond when about a dozen people corrected it. (I mean all things considered he almost surely just got confused and knew where it was filmed since that was hardly a secret, but kind of annoyed there was no “ooops my bad”.
Don’t get me wrong, he does clearly know people involved somehow so it might be right. But given most are predicting this and for some reason he felt comfortable but no other entertainment source had reported this, it also feels like one of those “I am going to say I got a source that told me the thing everyone already assumes will happen will happen… then I can say I told you so when it happens”. I mean seriously even if it ends up going to HBO MAX people have been predicting that since before DC Daily got cancelled and started the latest round of “DCU is done”. And two other shows have already dropped on HBO MAX also, and Stargirl is moving off, So is that really proof of a source? I would be more impressed if someone said they have a source Titans would continue to be exclusive to DCU and it came true.