That is because they enjoy a fixed relationship with the Right Shoulder during the Pivot's Delivery of the Power Package into Release (6-K-0), and there is no independent motion of the Hands until they have been delivered to the Release Point.
Is this what is meant by "staying connected?"
Not really . . . I think that the "staying connected" thing that was popularized by Jimmy Ballard is very much different than what has been described by Pokechop. The Ballard connection is FORCED . . . where as the loaded #4 Pressure Point is a connection CAUSED BY FORCE . . . the down plane thrust of the right shoulder.
Take a few hard swings left hand only keeping the left arm SOFT. You will feel the "connection" . . . but it is not something that YOU HOLD . . . it is something that is caused by LAG and the pivot blasting the left arm into impact.
There is "Ballard type connection" and then there is G.O.L.F. connection . . . I'll take the latter.