Very simple: I have disabled all vibrations, but my Pebble Time watch vibrates anyway, at the start of the alarm process, with Sleep As Android. It is not how I want to get up. I prefer only music and my new lights. The vibration wakes me up before any of this.
Also, BTW, the alarm on the phone keeps repeating the weather over and over after the alarm termination. About 7 times.
I will send a bug report.