How do you know there wasn't an emergency? Not everyone decides to announce their personal business to every one, some people do sll retain a shred of personal dignity about their own circumstances.
But you're making it up, Dunkmein! They haven't for one moment suggested they had an emergency. Don't you think that if that were the reason they might have told OP, not least because she's more likely to be sympathetic to that excuse than the pathetic one they've come up with?
However, as I also said, it is good practice to check whether the appointment is still needed, irrespective of the OPs dads advanced years. The home owner might just might be indisposed and not able to cancel the appointment. Note use of the word might
No, it isn't. How often do you get texts from dentists, plumbers, electricians, hairdressers, opticians, lawyers etc asking on the offchance whether you still want that appointment you specifically made with them? I never do - probably due to the fact that they reasonably assume that if I need to cancel the appointment I'll, um, cancel it. Why would someone who needs to cancel an appointment wait around for the other person to get in touch? After all, you can't guarantee that someone will see a text: suppose their battery's gone, or they've lost the phone or, like me, they just leave the phone in their bag and only look at it occasionally?