So much to write here - but little time. In short, it depends on the language of the new contract. In some cases there is a clause that mandates that labor cats (e.g. wage rates) will not be affected, in some cases that language is not there. Further, it depends on whether or not it is a FFP contract or Cost Plus - or something else. If it is cost plus, then you are generally going to get the same wage that you had before. If it is a FFP - then the new contractor will be looking to scrape every last penny they can get and everyone should generally worry.The other thing to look at is whether the contract has shrinking costs built in - if so you may be in for a squeeze.
Take the X+Y now, negotiate with the new prime and see what happens. All that said, people with tickets keep jobs in this market. You may have to take a pay reduction to keep said job if you do something very generic. But if you have any skills whatsoever, then you're not going to be unemployed any time soon.