It's the total lack of any clear suggestion as to the "how" that's bugging me.
Even him just making some vague statement as to what's going to make that possible is how you build suspense/intrigue. Having a simple declaration of intent alone doesn't really excite me.
His progression so far has basically been:
6.1:Wants to start a war for the 13th's salvation somehow.
6.2: Wants to start a war for the 13th's salvation that involves the moon somehow.
6.3: Wants to start a war for the 13th's salvation through death that involves the moon and breaking down the boundary to the source...somehow. Has Rubicante destroy the voidgate so we can't interfere for the time being.
Compare to Elidibus in 5.0, where his progression was:
5.0: Wants to end the Scions using warriors of light.
5.1: Takes Ardbert's body.
5.2: Starts masquerading as Ardbert, moves to build faith in the warriors of light, then awakens people to the Echo. We now have enough information to get the gears turning and start seriously questioning how he's going to execute his 5.0 scheme.
5.3: Is revealed to be a primal, at which point things clicked for a lot of people and understood why he was doing what he did.
The problem to me is that Golbez is not setting up anything for us to actually parse information from or at least try to in some meaningful capacity, and it's feeling like everything is just going to be dumped on us all at once in 6.4.