Device connection notifications to Alexa / HomeKit that can spur automation

Given the link to Alexa/HomeKit (especially Alexa)

Being able to have a notification that kicks off an automation would seem to be straight forward.

Example:  “Mothers iPhone joins the network”. - could then kick Alexa to “turn the heating up”

potentially this could be used for zoning as well - if “Bobs laptop connects to the Wi-Fi in the office between 8-9 - play the news”

it would also help with an audible announcement saying “an new device has joined the network (would you like to add it to a profile) to help with compromise.