In a community where it is acceptable to break up via shadchan at that stage, then that would have been a much, much better choice, with all respect to this rav. A text message has the air of a quick, emotionless check-this-off-the-to-do-list. It removes the responsibility from the guy- he doesn’t need to explain himself, he doesn’t need to face the consequences of his words and actions…
At least the shadchan would ask for an explanation.