For those being let go - I would deffinately seek some friendly advice before submiting anything - official or otherwise. I think a quick call or email to your status rep and/or the training comitee would be appropriate. Even as a probie, you are entitled to representation! - and most reps at most of the places I've been are very prompt in returning communcations. You may be one of many this is happening to, and the union needs to know that.
The company needs to be upfront about anything going in any sort of record, and you need to be able to collect unemployment and any other benifits the law dictates that you are entitled to.
(Disclaimer - I don't, nor have I ever, worked for ATW. I have worked for a ******y regional, though.)