I think the new strategy–basically to match a spacecraft to a boosters six to twelve months out based on spacecraft readiness–is enabled by the studly to-orbit capabilities of the Delta IV and Atlas V EELV vehicles.
I’m guessing both families of boosters have enough margin that they can wait until later in the scheduling process to be matched with a spacecraft versus the traditional way of matching much earlier on based on which booster was the best fit (or the only fit) to get a particular satellite on orbit.
This flexibility allows a spacecraft to go to either a Delta IV or an Atlas V and avoids committing to one versus the other two years in advance.
The idea makes plenty of sense. The only ones who might lose out will be those secondary and orphan types of payloads looking for a cheap(er) ride to space.