Based on what you have outlined above, it is illegal. The key here is the fact that the employer offers a group health plan. Option could be to up their compensation.
OK. I could be wrong, but I think under current law and regs you are stuck (i.e., can't distribute) unless you go through the steps of a spinoff termination. If you don't go that route, then hopefully the plan has language that would treat an employee's termination of employment with the former sponsor as a distributable event even after it's withdrawn.