There was some talk on various forums and other sites prior to the Pro Box being announced that you would be able to watch recordings stored on the main box on a new version of a multiroom box that hasn't appeared yet.
Multiroom was covered in BT content supplied as part of a business briefing at the tail end of 2020. It doesn't mention sharing from a main box specifically, but people that were on the call have suggested it is a feature, so we will have to wait and see.
A number of bits of kit (from cars to routers), are still behind schedule due to the impact of the pandemic and semiconductor shortages. There is also supposed to be a new Smart Hub 3 (and complete WiFi discs), on the way which support WiFi 6.
A router/disc/tv box mesh WiFi perhaps?
