Silence Unknown Callers Shortcut

Yes, at least in part. I don't think you can create a shortcut to actually toggle the setting, but you can create one that opens the setting page:

prefs:root=Phone&path=SILENCE_CALLS

You can invoke the shortcut by name in Siri and then turn the setting on or off as needed.

Regards.

Why do you need a shortcut? All you need to do is turn on the switch and it is taken care of.

I understand. However, I've always looked at that switch as something you turn on and leave on. But then if you are expecting a call from someone you do not have in your contacts, such as a doctor, or other emergency type call, I can understand. I may have also misunderstood, when it seemed you wanted to turn it on if you were expecting a call. It is found under Settings>Apps>Phone>

You're welcome.