Yes, I wonder how it will be operated. With the shuttle train kept to this track, I wonder if schedules will be modified for the NYC bound local train to be at the platform when the express arrives. Right now the typical off-peak practice is for the shuttle train to come out of the yard a few minutes - several minutes after the express has left, right?
A local train waiting on track 5 with doors open could theoretically provide an easy crossing over to the island platform for arriving NC branch customers. I don't know if that kind of crossing pattern is something the railroad would want to encourage, but it'd be a whole lot more convenient than going up and over.
Ultimately, Bridgeport station is going to need significant expansion (or Barnum, if we're gonna play it that way), and I could see this informing that design. Ideally the stub end track would be between the local and express tracks to better facilitate transfers via an elongated and widened island platform.