I’m sure the transponders needed to access/cross the city centre would be given to any city or emergency vehicles that needed them, same as the buses - the point was more that every residential address is still accessible by road for those special cases such as deliveries, garbage collection, trade vans, emergencies, etc., even when you block roads to prioritise transit and cycling

Emergency vehicles generally have unrestricted access as far as I know, which also makes car-restricted infrastructure far superior to regular car infrastructure, on account of not being congested by cars.