@Zeues-1992 Well, there is probably an outlandish outcome where idk, the sun happens to explode at that moment or, some alien race accidentally shoots a planet destroying weapon at them.
(This also plays into the weird nature of crossing alternate dimensions/timelines.) Or Revenant from others world somehow travel there. This is why the traveling parallel dimensions is weird. Since the other Revenant is in an alternate dimension/timeline, would there be another timeline or something where Revenant travels to "our" dimension and does something different? It's weird, I should probably make a diagram.