Exactly right, distribution is in place. And, therefore, it must be maintained. Tree limbs cut, poles replaced when they rot, wire replaced when they fall during ice storm, hurricane, etc..
Yes, increased usage (with decreased price, esp if used to replace natural gas for heating, hot water, cooking) and then possible electric vehicles would mean upgrades to the distribution system as well. Also, if twice as much power is sold, cost to “deliver” a kw-hr is less (not quite half, but likely close).
Yes, the HV transmission system would require far less in the way of upgrades as new load is taken up by “nodes” of 50-100 FF modules at less centralised, and closer to urban, locations. But, one of my main points, that the first 5-10 years would see repowering existing plants, which have much of the infrastructure already in place, with transmission systems designed for power to “go in here”, is not contradicted by any of this.
I’ve been assuming that the “distributed” power was, as had been mentioned elsewhere, powering individual buildings (large offices, skyscrapers, malls, etc. It is that kind of use that I see as farthest down the road, and as having the least impact on our world.
The reduced cost, vastly reduced environmental impact, and just as vastly increased availability of power will all be more important than any reduction in need for centralized plants. In my opinion.