It's not expected, but makes sense to me sadly. Sorta like if someone had a massive install, is on year 19, just put 11% more panels, extend the whole system for another 20 years...sounds a bit crazy and lopsided. I think most of us would agree NEM1.0/2.0 is very benefical for most homeowners.
That said, they should allow folks to pay some $$ now and install a separate meter if they want the upgraded section on NEM2.0. I'm sure installers didn't spell it out and verbally just said what was most beneficial for the customer to get the install done. Utilities obviously have no clue neither as they give out wrong answers and a lot of us (me included), just figured it'd extend (which sounds lopsides to me).
The letter matches the FAQ you/someone else posted earlier.
If installing a new meter for a couple thousand is allowed, everyone should do that if their upgraded system was big enough. That seems the most fair to me.
With all this NEM3.0 talk, I'm sure a lot of folks are now wondering and the utilities are probably reviewing more install docs possibly.