FWIW, we considered this technique back at Pebble to make notifications more actionable and even filed a patent for that (sorry!) https://patents.justia.com/patent/9411785
Back then on iOS via ANCS, the watches wouldn't receive much more than the textual payload you'd see on the phone. We envisioned to be working with partners such as WhatsApp et al. to encode deep links/message ids into the message so one could respond directly from the watch.