You get an invite to a conference as a keynote speaker, which is then rescinded, for no good reason even? That's a big deal. I don't know about "heartless" and

You get an invite to a conference as a keynote speaker, which is then rescinded, for no good reason even? That's a big deal. I don't know about "heartless" and all that emotional stuff, it's just plain disrespectful. You make up your mind about that kind of stuff BEFORE the invitation.