If your on the seniority list at YX, go to the local Facebook page. You will find the info you’re looking for, and yes less then 15 went to the Big 3 last year as pure civilian hires. The volunteer who puts the info together is pretty transparent, and the spread sheets are all there for your review. Yes some (14 I think) I a blank spot for where they left. Also you can get info through ALPA for United, and maybe DAL. American isn’t going to happen for most civilians at YX, so probably stick to the other 2.
Most seem to be going to Southwest, JetBlue or Spirit.
Try to get in the training department early, or try to get a union leadership position.