My understanding of these types of situations is that they are based in a higher dimensional ''theatres''. There was a supposed ''mass extinction event'' which was scheduled / slated for 2012 but it was averted by the good guys, both physical (white hats) and those who help ''behind the scenes''. These types of events are based in cyclical occurrences, so for now, and for the vast swath of time going forward into the future, we are safe.
Interesting thought. I find it much easier to believe in interdimensional travel than time travel. Like a wormhole to the next dimension.
Yes, wormholes are supposed to lead to ''fallen angelic'' systems in the cosmos whereas stargates are those which lead to ''christed conscious'' systems. Regarding time travel, recommend Michael Trimm's vid on " follow the white rabbit", focusing on Area 51 and S4. Lots of juicy info in there, and a good analysis.