Adding a channel to an application usually means finding every place that sends a message and teaching it a new delivery path. That is how channels end up half-supported.
Here every automated message is a catalogue event, and which channels fire for an event is configuration rather than code. Adding WhatsApp to booking confirmations is a toggle, not a deployment.
The words are shared. One template per event per channel means the property writes its confirmation once and it reads the same on WhatsApp, email and SMS — and resets to the shipped default if an edit goes wrong.
Connection is a scan or a pairing code against the property's own number, so guests see a sender they recognise rather than a shortcode.