Without a CBA There would be no language to force the employees at VA to be part of the transaction.
We as Delta pilots should however make every possible effort to force the management teams to bring the pilots over. I suspect the price of that support from Dalpa would be a prenuptial agreement on the SLI.
I think this is simply a wild rumor however I do find it interesting that Delta management has put out that they need 50 additional narrow body airframes for the domestic system in the next few years and they were looking at used options.