The letter seems to be a specific response to the enormous industrial grow facility that Oakland was planning to allow. Although they certainly dont limit any action they may take against anyone, imo its clear that it is the plan for that particular place, which has received a lot of publicity nationally, that they were looking to threaten. It doesnt seem to signal any changed approach. If you read enough about the Montana raids, they seemed to specifically target mmc's that they felt there was evidence against regarding black market activity outside the state law.