That sh!t wouldn't fly in California where the BAR, (Bureau of Automotive Repair) would be all over the manufacturer for "impounding" a vehicle on a routine service. Having worked 10 years in the automotive business back in the 80's and early 90's, that simply wouldn't happen. The parts would be ordered and then the customer called to bring their vehicle back in for the recall to be performed. Otherwise, the dealership would have to put you in a rental if it were that critical to get done. These kinds of things lead to very bad press for the dealership and the manufacturer so they don't really happen or people would avoid these brands like the plague.
In California what happens in recent times now is when you don't have a critical recall done is the state holds up your registration until you've done the recall. Ask me how I know this? My Honda Odyssey had a critical fuel system recall and I was forced to comply with it at the dealership before I could get my vehicle re-registered for the next calendar year. I was sent a notice from the NTSB and manufacturer that this was an urgent critical recall that must be done in advance of when the registration was due so I could make an appointment with a toll free number they gave me to call. Also, the dealership had the parts or would have them within a day or two to complete the recall on a reasonable schedule. It was that simple. This was all news to me and I wouldn't have believed it if it didn't happen to me directly on two different vehicles. The dealership will not "impound' your vehicle on the spot but give you a time and date to take it in and have the recall handled in a timely fashion. If it gets done before the registration due date, you'll never get the delay and nobody will be the wiser. This is how a "forced" recall is done in California now and 2 of my vehicles were actual proof. It's rare that a recall is that critical but in the case of the two cars I had, they were fuel system related and another was that Takata shrapnel air bag or SRS safety system related recall that went around by many manufacturers. My wife drove that vehicle and I wasn't going to risk her life with a defective air bag that could do more harm than good if deployed in an accident, so yeah, I wasn't going to blow it off anyways. An explosion or fuel leak possibility and certain safety items will get the mandatory recall response triggered from the Feds NTSB & State.