He's been gaslighting people left and right. At this point, I am convinced that the screw up in season 8 of the original series was his fault and not the 2 showrunners. I say that because RR Martin suggested they were the guilty party - and given how much he's been gaslighting people about everything else, we can assume he was gaslighting about that as well.
I'll wait until this and other shows are done by this creep - if peeps say they are OK and have decent endings, I might watch then.
It isn't that he's writing slow, it's that he's telling people he is having writer's block while simultaneously churning out prequels, spin offs and source book type releases. It gives the appearance he's dragging this out before a Song of Ice and Fire is finished and people lose interest.