It’s not a critical problem. It won’t block anything. There are already possible solutions. As you said, utilities have been rolling out time of use metering for half a century, and already want it everywhere. My EV already has scheduling that can take advantage of that, and time of use metering would give me incentive to use that

It’s also not hard to imagine a service that could more intelligently coordinate the load for very low impact: I already have such a thing for my air conditioning