He asks: “What about the negative extraterrestrial spirits, will they continue the programming if left to themselves following the alien withdrawal?” What can Creator tell us?

This may well happen with some. Keep in mind the extraterrestrial lost souls will still be present for some time, and that can be made a concentrated effort of the healing work to remove that as a negative influence. So just as with all programming of human beings, there will be longer-term consequences because so much damage has been done to contaminate thinking and corrupt inner beliefs.