The impression of the person that I spoke to was that this email was to encourage people to move off cable cards, and they were not necessarily discontinued. But he advised to call back in a few days as they learn more.
This is about Charter's announced plans to move to high-split for higher HSI speeds, and the need to terminate CableCARD support to do it[*]. Actual schedules for those HSI upgrades will very substantially between locations (perhaps many years for some), but as some predicted would happen this is the initial carrot. The more people who volunteer for the offers on their own schedule the fewer people Charter will need to use the stick on later as they actually schedule a location for high split rollouts (which will almost certainly include more email, announcements on bills, and snail mail announcing "drop dead" dates). Note that those drop dead dates will likely also require some customers to replace their STB with a more current model. And, as others have said, there will still the those that are "surprised" that their TiVo stops working (it is a classic horse and water problem), but given that more people are clamoring for higher speed HSI[**] then CableCARD support, this step was sort of inevitable and expected.I just got the spectrum email as well about the cable card. It isn't clear what they are going to do or when.
Until the drop dead dates are announced for a location most expect TiVo's to continue to work and be supported as good as they do now (yes, that is not saying much for some locations).
[*] There are a whole set of very expensive alternatives that were proposed over the years that could keep CableCARD support limping along across the entire Charter footprint (the cheapest would have worked only in limited areas), but given the very small numbers of CableCARD users Charter is not willing to even consider spending those many many millions, especially now that they have no legal requirement to consider doing so.
[**] And at least a few proposals currently being reviewed at the FCC define new HSI tier minimums that would require higher speeds to continue to be considered meeting one's requirements to being a HSI provider and obtaining federal funding for expansion.