I think this is very subjective. For instance, I've got a call from work that I have to work 48 hours on weekend a night before the match. Is that a good excuse or not?
It's not.
You gave your name to hold a timeslot for your hobby, knowing full well that you'd be on call, or subject to call-out, whatever, for work during that timeslot? And knowing full well that you wouldn't tell work to go fukc itself? It's simple: (1) Thank you for letting us know. (2) Work is important and we don't need you getting fired and ending up homeless over
a sport. (3) You forfeit your match fees.
It's just like in hotels and air travel. I'd cut you an awful lot of slack if you told me that you had to drive a family member to the hospital, or if you lived 60km away and got snowed-in, or if Liberals declared the bridge between your house and the match venue unsafe due to some bad words in some graffiti, of even if your babysitter phoned in at the last minute to say she'd gotten chlamydia from you. But not for the reason you hypothesise. And I say this as a former match organiser, official, and director.
Why, you ask? Simply because someone else prolly wanted that time slot. Someone else prolly got inconvenienced because they couldn't
get that time slot. Maybe somebody else stayed away because Saturday 0830, or whatever squad it was that you filled to capacity and then just declined to show up for, was the only squad they could manage, what with the wife's Australian Rules Greco-Roman wrestling practice, the boy's' Ouija tutoring and his little sister's harpooning class, and the wheelchair-bound mother-in-law's regular ride to the liquor store for her case of Balvenie.
So. Unless we can fill your spot with someone who's been standing there waiting for a cancellation, armed-up and ready to fill your boots when your squad walks out to the first stage, you forfeit your match fees.
But yeah; that's all very subjective.