Originally Posted by
Iscah
I'm not sure what you're picturing here.
The whole point of the time-travel plot was ensuring that we couldn't have a stable time loop, because that would lead straight back into the Eighth Calamity and the exact dark future that G'raha was trying to prevent from happening.
(If he'd failed his mission and couldn't save us or prevent the Calamity, that would result in a stable time loop - his actions are part of the overall timeline, even though he didn't successfully change anything.)
The events of Shadowbringers seem designed to "drive a wedge into the loop" and force us to take a different path from the natural flow of time, by making it impossible for circumstances to lead to the events he knows as history.