Puma's Westford HQ is a little less than 5 miles from the Littleton stop on the Fitchburg Line, and MRTA has a bus route out of the station hitting Puma, IBM, and downtown Littleton. So their employees have long been able to enjoy car-free or car-few commutes.
Using the trip planner, just the commuter rail ride from the Littleton stop plus the orange line transfer is 1:05 for the South Acton Express and 1:20 for the regular stops. Plus you have to account for ensuring you make it, delays, etc, not to mention the drive time.
The existing workers aren't going to find any comparable job near Westford, so regardless whether they get laid off or not, they will need to move.