Devil's in the detail
When the govt sets up a deal like this they usually give in to some stupid demands from the private sector. I'm expecting these homes will initially be limited to just BT as their ISP. After a few years some regulation changes will allow other ISPs in but BT will charge a lot for access to the last mile making it difficult to compete. BT's pricing will be "special" for these new homes, they'll say the new tech is more expensive to run, so the monthly ISP bill will be lots more than copper connected homes.
Yet another thing to consider when buying a home: is it one of the new-build FTTP properties where you get fleeced every month for internet access?