Yes, there is an exception to notice requirements for health and safety. If the regional center needs to change your services to protect your health and safety, they do not have to tell you in advance. The regional center has 10 days to give you notice after they make the change.§ 4710(f). The deadline for you to appeal starts when you receive the notice, not when your services change.
In all other situations, the regional center must give you notice 30 days before it changes or stops your services.