Did psychic Sylvia Browne see so many people as living their last lifetime because the potentials at that point were aligned with extraterrestrial annihilation of humans?

Sadly, this is quite true. It has been interpreted as a positive thing by many, as so many individuals do wish to leave and be done with the earth because of its difficult nature. And this has been exploited by introducing the promise of ascension where all will be raised up and transcend their current existence by moving into a higher dimension and will no longer be incarnating in the physical in the same way. So the prospect of serving out one's current sentence but then graduating into a whole new way of living is a quite attractive notion, but this, unfortunately, is quite disempowering if it diverts people away from seeing the real hazard in front of them represented by extraterrestrial manipulation which could result in the end of humanity altogether. It is better to be aware of such a threat and take action than to be passive and wait for a grand awakening that may never come. It is very likely the case that any psychic who achieves prominence has been held back in some way and constrained to not reveal too much. So there is heavy mind manipulation going on for all those in the public arena so they will not go in dangerous directions or nose into the darker side of things and then begin to unravel the threads leading them to the deeper truth about who is running things and how it is done. So you will see in general a systematic focus on positive agendas across the board. And so all are in the grip of mind control, letting them do their thing in other respects, but not allowing them to turn to the deeper issues.