It's just ridiculous for companies to expect loyalty of any sort. Of course you don't screw people over, say like promising to not look at offers for a certain time but then leave or giving one day's notice.

But if a company needs to cut you and contract out work, they're going to do it. Sure the individual manager might not like having to lay you off. But he will do it.

You should avoid duplicity, but in the end you have to take care of yourself and your responsibilities first.