If utilities don't do retail metering, consumers can get similar results by pooling their loads. Solar cogeneration is short-term steady while most domestic loads are intermittent, which means that over an hour a consumer might be a net provider to the grid but get charged amost as much as without cogeneration.
On the other hand, a buyers' co-op smooths out the load variations and approaches the effects of net retail metering. Which is appropriate, because (unlike wholesale rates) cogeneration does not put extra load on the grid.
If utilities don't adapt to these realities in a more realistic way than offering wholesale (i.e. solar plant) rates to cogeneration providers, they're likely to see a lot of pressure for cities and especially smaller towns taking over last-mile electrical distribution to get the same effect.
This last is not completely hypothetical; at least one Sunbelt town (mine) is moving in that direction.