"Imputing it does NOT exist is quite another. "

The statement on the page to which you refers states

"Send notifications of flight departures and arrivals, delays, cancellations, seat upgrades, and much more"

These sorts of things I would expect to be notified on where possible. QF does notifications on delays and cancellations. It doesn't say that it would notify you of a change of equipment and, I too would be surprised if they did

Dave