smccloud I don't think they have ever just called it High-Split upgrades internally High-Split only refers to the diplex filter split range.
They do have a timeline list of when an area is going to be upgraded internally but they aren't going to release the schedules to customers because they can lose their job if management finds out they spoke about it. That timeline has slipped for areas and likely is updated often with it being moved forward in time for completion.
I have a feeling Charter is getting ready to either rollout 2gig in areas completed in North Texas and other phase 1 areas or is prepping the frequency slots for it.
Looks like they are going to move secondary local channels to SDV in all markets to free up QAM space for OFDM. Which seems efficient considering how many more QAM carriers LA, Dallas, and NYC have had to reserve compared to places such as Ohio or Florida.