NJI pilots are protected by the McCaskill-Bond Amendment.... The VSL date of hire integration has not been "given" to them. It's the law...plain and simple.
I haven't researched McCaskill-Bond but it has come up in some threads with rumors of JetBlue merging. I believe it states that both merging parties have to be represented by a union. In other words Non-union NJI would not be protected by this legislation.