I'm pretty happy as the lore develops that my pod'n'planet story might be reasonably close to what will happen. One thing that I've seen around is the idea that the capsuleer built stargate will end up being either in Thera only, or in the shattered star systems. I don't think this is a good idea.
(I'll call this thing just a stargate, though we'll really need a new term and I won't be so self-centered as to recommend that my "throw-gate" from the story be that term.)
Following The Prophecy too closely?
It seems like it would be a lost opportunity for the stargate to only be buildable in Thera. Capsuleers combining forces against the empire sounds great, but it goes against the player-generated content theme of Eve. Do we really expect that CCP staff will have an ongoing grand event to command a series of fleets to attack the player-built stargate to fullfill the Prophecy trailer? Do we think that CCP would rally Empire-loyal capsuleer corporations to do their proxy work? We've seen what happens when CCP led player groups try to achieve an objective and the null/low powers decide to interfere - I wouldn't put much ISK on the Empire if they were actively opposing a nullsec/WH player group.
Sidenote: If The Prophecy trailer is literally a prophecy then of course we know that the capsuleer stargate cannot be in Thera or any wormhole, since the trailer shows an Avatar Titan coming to the attack. But I think that's a bit too far to ask of the trailer.
Construction in the war zone
In either of those cases we'd be talking about building a huge structure in a system which has no moons and thus no POS for manufacturing. So all components would be either built in the stations or flown in. Unless of course the new starbase design allows these to be more freely anchored. And of course we're talking about building this thing of unprecedented cost in the system with the most ISK destruction per day of any system in New Eden.
Why limit the great land rush?
Limiting this to Thera only also would imply there is only one such capsuleer stargate. That misses the opportunity for a race to the great land rush that would motivate the building of the gate in the first place. What motivation will a group have for building this massive project if there is no competitive advantage that they will gain?
Limiting it to only the shattered systems means more than one capsuleer organization can undertake it, so that's good. However there is still the matter of being able to control the location of the stargate. Perhaps it is too much to let the great nullsec powers (who are the ones who will have the resources to do this) bury their stargate system deep into their own defended systems. I would expect that when coming into operation every gate heading to the stargate would be bubbled and defended to reduce the ability of a cyno ship to slip in.
On the other hand, there is something to the idea that such big nullsec powers would have to stretch their forces out to claim a shattered system and defend it to build such a thing. As we read recently, nullsec forces don't quite have this WH thing down yet. But if you're a WH dweller, do you really want the great null alliances moving into the neighborhood and bringing all their baggage with them?