You are right about the
You are right about the problem with service revenue, however, there is nothing in the franchise contracts which identifies servicable parts for the dealers (confirmed this with a buddy who owns three new car dealerships). In fact, there is nothing in the dealer contracts which define product lines or product descriptions. Manufacturers are free to to produce whatever type of vehicle they like and in most cases (not all) the dealers are free to purchase whatever vehicles they like for their dealerships.
The bottom line is that the dealer/manufacturer relationship will need to be re-negotiated. There will be not be "thousands of plaintiffs" since as my friend pointed out, they have a national association which would represent their interests in negotiating with the manufacturers. Some of these changes are already in place. Chevy dealers get an under the table "servicing offset bonus" for each Bolt that they sell.
The dealers will cooperate because their biggest fear is that if they don't, the manufacturers will setup their own stores to sell Electric Vehices and use the Tesla model. They actually know that they don't have a great deal of leverage here.