Check the document, but that prior service is going to count and I don't think you can delay a re-hire's participation on entry dates, usually it's immediate. Even if you are able to exclude until after a YOS using rule of parity, participation (other than deferrals) is retroactive so you're in the same boat. Two years eligibility doesn't help either. If they never had a plan until now, maybe it's different, but I don't think so.