In the future, do you think CBB rates will allow people with older packages to upgrade to faster speeds at the same costs as before - or is the model to always require a customer change a rate plan to get new speeds?
I doubt it. If you're on a grandfathered plan - one that is no longer available for new subscribers - you'll be allowed to keep it, but if you want to switch plans you have to choose from one of the current packages. That's how it's always been.
the bigger issue is that you'll need a newer 24 channel modem which TPIAs can't get right now i think (even if they could get it, i doubt they want to offer it with current rates).