I think it's the wrong time to use the phrase 'you don't need to take any action'. You can say that when it's a new version being released without any breaking

I think it's the wrong time to use the phrase 'you don't need to take any action'. You can say that when it's a new version being released without any breaking changes but not when you're shutting down a service! You must look for an alternative and implement a migration, that is action.