Dismantling POTS system may shift the scope of this regulation to cell towers.
I doubt it. Look where they are sticking cell "towers" now. Building roof tops, church steeples,goofy looking fake flagpoles, on top of billboards,etc.. There is no way they are going to be able or willing to put big generators at all these sites.
When all these mini-sites go down the load is shifted to the real cell sites and they puke. During the last 3 big power outages here in my state of Connecticut cell service became very unstable. You had "5 bars" but if you tried making/getting a call it failed. POTS kept working like normal.