Grandfathered, but only for a while.
With NEM 2.0, there were changes to terms and a connect fee. Those of us with original NEM were supposed to get to keep if for 20 years from original date, then be switched to 2.0 (without the fee.)
I did pay a $300 fee for time of use meter (or maybe that was net metering meter), which was obsoleted and replaced at no charge with smart meter.
Something like grandfathered with original equipment requirement (I get to swap old inverters with other old or less old models, don't have to put in the latest standards.) And we were supposed to keep original terms for 20 years. The planned 3.0 was going to cut our time short. Not sure in the event we were already moved to 2.0, if that would immediately bump to 3.0 anyway.
Of course, $/kWh changed along the way, time of use vs. rate changed, and whatever tariff we were on was eliminated. They said we would automatically switch to a new one, or could choose an "even better" plan. Then San Jose was going to swallow up all customers, consumers first and PV producers second by default. They offered pricing just a smidgen better. I opted out, remained with PG&E. There was a form to check off, including "Why?", which included "Because I don't like being automatically switched."
In the event a customer turned out to be a deadbeat, they would be transferred back to PG&E. San Jose gets the profit of good customers, PG&E takes the loss of the bad? How can they do that?