I do not believe average smartwatch users understand what they’d be doing if they got this. I do not believe vendors integrating with such a thing can do it safely, or even that all vendors integrating are good actors.
One reason iMessage is less of a total cesspit than SMS is that the ecosystem is closed, and makes automation difficult. It used to be impossible nearly, and in that era we had almost no iMessage spam. Now it’s difficult, and we have moderate iMessage spam. But adding hooks to make this automation easy, and worse, leave the trust environment as a feature is just wrong.