So what do you make of what he said in that YouTube video? I'm clearly missing the logistics of it, unless you mean they WILL use local data centres due to exchange space being too expensive and potentially not even being available at all (lack of space in smaller exchanges + Openreach ultimately closing them)..
Take the Cablelink feed, put it into a switch, rent some metro capacity from Virgin Media or A N Other and get the customers to a local colocation facility.
Alternatively Cablelink into a switch, that switch to another in an exchange where there's a handover, rinse and repeat until you get near a DC then rent metro capacity to the DC.
This is how Sky's network is built - daisy-chained switches in exchanges until within economical range of one of their PoPs.
No need to put anything in exchanges other than switches with 10 gigabit ports.