Thank you for responding. It's nice to get some validation for my experience. I think that the various traditions have different words for the experience, as well as slightly different expectations for what it "should" be, although I may be wrong. I'm in no way an expert, just a participant. Maybe someone would like to write more about these different states or terms.

I guess I would suggest that anyone interested in understanding whether mindfulness is just exposure therapy go to a few meditation classes with more advanced meditators and listen to them describe their experiences. Usually, in the classes that I have taken, we all describe our experiences in the meditation, and they don't resemble anything that would be considered a reaction to exposure therapy.