I'm sure Tivo can make it work with existing hardware, and will for the MSO branded boxes. But that doesn't mean that cable companies would be willing to cooperate with Tivo to come up with a solution for consumer owned boxes. That's just added work for them with less revenue, when they are already de-emphasizing TV since they make more of their money from internet these days.
So I don't hold out any hope that my Bolt will someday be capable of working with IPTV delivered Mediacom (and if it did it would probably require updating to TE4 which is a non-starter for me) Whenever they drop cablecard, that will be the end of my Tivo, and the end of my subscription to Mediacom. I keep one eye on Tivo forums where people are already investigating other options. One good possibility looks like Channels DVR, which is able to record the live stream from the "TV Anywhere" provider logins for most cable channels.
TiVo has a new line of hardware and software that they're selling to small/mid-sized MSOs for their IPTV services. See here:
Among the few that have struck deals with TiVo so far, such as TDS, they're using customized Android TV STBs that are skinned with the TiVo UI.
None of the traditional TiVo DVRs (with QAM tuners and hard drives), such as your Bolt, will ever be updated to work with any MSO's IPTV service. And to the extent that *any* TiVo box works with IPTV, it's because TiVo and that IPTV MSO have a deal in place for TiVo to provide the STBs. There is no industry-wide standard that will ever allow a retail box from TiVo (or anyone else) to be purchased by a consumer and then used with whatever IPTV service he/she wants, the way a CableCARD-equipped TiVo could be used with any QAM-based cable TV service.