Hmm, If I want to disable Win Defender, I don't change any of the settings for it's Service in Services. I just turn off Automatic scanning, and Real Time Protection from Win Defender options, and it turns it off. I don't get any notification to turn it back on.
Of course, you could un check Spyware and Related Protection as well as the Virus Protection in the Action Center settings as well.
But I have Avast installed, which has a Spyware module built in, so I guess it replaces the missing Win Defender notifications when it's turned off.
Why do you want these turned off anyway?