Originally Posted by
Cleretic
I think that we're just looking at a moment of convenience-based storytelling that, in-universe, sort of just manifests as a 'weird it happened twice' thing.
Heritage Found synced up with the outside world at around when we busted into Vanguard, just as the First synced up with the Source at around when we crossed over. But in both cases, it's correlation rather than causation; there is no suggestion that the transit actually caused that sync, rather that it just happened to line up, and it lines up just because it'd be a massive headache to factor in 'time flows differently between shards' in a game with a largely consistent world.
I could possibly be convinced to believe that Heritage Found wasn't coincidence and we're looking at sort of a temporal instance of something like 'two connected containers of water equalize in pressure', but I don't think that would explain anything outside of Heritage Found specifically.