It will also lead to an increase in preemptive cancellations for both winter storms and summer convective activity, I suspect. The carriers will be much less likely to take a chance on summer diversions whilst waiting out a CBs at the destination. And in the winter, the delays associated with runway closures/plowing and deicing queues might also lead to more outright cancellations.
Most feel these new rules trace back to the Colgan stall/crash in upstate New York several years ago. Don't want to really debate that, but I feel that the rulemakers have shaken things up more than needed.
As for long duration commutes, I know pilots in MA that leave BOS for JFK or LGA at noon or earlier depending on weather in order to crew a TATL flight leaving JFK between 4-6PM. I think this sort of thing is rather common actually.