The changes to the position and hold rule have made it mandatory for the local controller to make complex transmissions such as this. One could only guess, that telling an aircraft on final to one runway about traffic that is holding in position on an intersecting runway, it is intended to raise the pilot's situational awareness.
Let me be clear that I am all for situational awareness. However, I believe that a pilot who exercises good situational awareness would recognize a conflict if the local controller cleared the departure for takeoff on the intersecting runway in conflict with the arrival regardless of the "heads up" transmission requirement.
Forgive me, because I am about to take another approach to this. So maybe the extra traffic information isn't for the pilot to maintain situational awareness but is meant as a reminder to the controller. If that is the case, then I believe that the additional workload of extra phraseology is a misapplication of problem solving to eliminate errors.
Operational error investigation teams are required to find solutions so that errors are not repeated. I've seen some excellent improvements and some that were implemented for the sake of showing that action had been taken. This requirement for additional phraseology came from a heightened level of scrutiny on runway incursions and surface errors on a national level. The scrutiny is well placed because, more than likely, the next major aircraft catastrophe will be on or very close to a runway.
Controllers are trained to "keep the flick." This rule does what I was trained to do in my head 25 years ago. Note to self "Don't roll this guy on 1 Right, traffic landing on 28 Right." So now we're thinking out loud. Sheesh!
The changes to position and hold rules, and the associated additional phraseology, have only increased the workload for already busy local controllers. It's too bad the FAA threw all of their subject matter experts (NATCA Safety Liaisons) out of Washington DC prior to imposing their work rules on Labor Day 2006. The desk jockeys could have used some real world input on this mess.