I may have an explanation for this.
The porn industry has an extremely high turnover rate for the most part. A few years ago, a friend of mine finished a degree in massage therapy (a legitimate degree, not the "massage" therapy kind). The porn industry hires a lot of massage therapists to help on set to keep actors going while filming scenes. He tried working in the industry for about a week before he got too grossed out and quit. He said during his time working on set, he learned a few basic facts about the porn industry from people he talked to.
1) The average woman spends only between one to six months in the industry before quitting. Any actress who stays in the industry longer than that is basically considered a industry Vet.
2) Most women quit when the demands on them on set are too much for them to handle. While he was on set on his last day, they were filming a deep-throat with swallow. After they cut, the actress walked off set and vomited right on his protective gear. They both quit that day and the actress in question had been in the industry for about three months and filmed a few dozen scenes.
3) The turnover rate for massage therapists is nearly as high as actors. See above for reason.
Soooo, if you see someone on NVG or CC and they seem to disappear after a few months, it's probably because they decided they couldn't keep up with what the industry/studios/pornwatchers wanted from them and they quit.
