Well at this point the purchase of the IP doesn't necessarily mean any of these companies will be keeping all these employees either. They could still sell Vigil's IP without any employees.
You're correct. The THQ letter to employees said THQ expected the buyers to keep most positions but some will probably be axed. Pay/benefits/etc may not be the same.
Without at least the core members, resurrecting technical IP from such a shutdown will be difficult (and possibly more trouble than it's worth).