BE CAREFUL - the "same desk rule" wasn't eliminated. The change allows plans to include "severance from employment" as a distributable event in their plan document. You'll need to check the plan document to see if "severance from employment" is a distributable event in the old plan; if not, the same desk rule is in full force unless the plan is amended. I work with a large plan that did not amend for severance from employment, and it's a mess when subsidiaries are sold-off and the buyer doesn't want to spin-off that portion of the assets.
I agree with masteff that you likely have a controlled group issue affecting the ability for participants to take distributions. It appears that the two companies are part of the same controlled group and that employees have essentially transferred employment within the controlled group. Generally, this is not a distributable event. Additionally, if the two plans in question are 401(k) plans, there might be some issues with terminating the old 401(k) and starting a new 401(k) within 12 months.
The best approach might be to merge the old plan into the new plan or alternatively, freeze the old plan and pay folks out as they terminate employment from the controlled group.