Personally I think they exist, but in an adjacent timeline. And since our timeline is getting wonky heading into the bottleneck event, they are seen then disappear because the timeline is, wavy, if you will.
It’s like your on a 100 lane highway in the center lane (our timeline) another car just drifts into our lane, or we drift into their lane. Sometimes there’s a hard swerve and you go 4-5 lanes over, recover and get back to center.
That’s how I see the timeline.
Ascention is the same way but up and down. Some on a lower lane, 100 lanes wide, some in a higher.
Just my thought.
Anyway. They come and go due to a time distortion.