Matt Birchler has a pretty common request for Siri, and that is the ability to schedule requests.
While all of these assistants can turn things on, turn them off, move thing up and down, and such, they can only do those things now. I can turn on the lights now. I can open the garage door now.
It makes so much sense for this to be supported. Sure you might be able to schedule actions inside of an app. But if voice is an official method of input, you should be able to do everything with it.
There’s not even a particularly high barrier in creating a delay/schedule system. The simplest method I can think of, is that when a voice assistant hears a request with a related time, all it needs to do is store that exact request (even plain text is fine), along with the date/time. Then the system can set its own reminder, and at that time, it simply performs the request automatically, and deletes it from the queue.