
Originally Posted by
Enla
My guess is that they're waking G'raha Tia up on the Source and requiring the raid simply makes their job of story writing a lot easier without needing to handwave the many months it took for the Crystal Exarch to start hero worshiping the WoL in the non-CT timeline. It's not really there to replace anything. They chose to bring back G'raha and likely hit a wall with their writing that needs context to be filled.
There is no "non-CT" timeline for the Exarch - there is a timeline where it happened in its proper place prior to ShB, and a timeline where it happened sometime after... which only makes sense if you don't stare at it too closely, but then it's not really trying to create an alternate canon, just hold things together enough to work for people who didn't play it in the right order.
In any case, whether or not you(r character) has ever met G'raha Tia, the Exarch
has met you in his distant past and explored the Crystal Tower with you. There's no need to handwave some alternate reason as to why he knows you because there's only one version of those events, whether it's in your past or your future.
Making CT mandatory doesn't just make it "easier" to write a plotline where we wake up young G'raha - it is an absolute requirement because otherwise he isn't there to be woken up.
Though as I said earlier, there are other events that would also require CT completion for continuity. Or they might just want to make absolutely sure that whatever happens to the Exarch in the upcoming story, you-the-player have full context and there is one established version of the WoL's interactions with G'raha that don't rely on an ambiguous "maybe this happened, maybe it didn't yet" format of story.
They made the ambiguity work in ShB but it does put restrictions on the story they can tell.