I lived with my parents on and off until I was 25. Whenever I was there, whether for University vacation, or when I was living with them longer term, the same expectation was on me - let them know my intended time home, and let them know if that changed.
I admit that at 19/20 I didn't quite "get" it - at University, I was coming and going as I pleased and they couldn't be worrying all the time about that, so why worry now? But it did make more sense to me as I got older. It's just courtesy. And I don't think I ever didn't let them know, even when I didn't understand why it was a big deal.
Nowadays, I live with a DP who works late shifts and is home after I'm asleep. As we don't share a room right now (late shifts and early rising toddlers don't mix), he texts me when he's home - meaning that if I wake in the night, I can know that nothing has happened to him, either at work or on the drive home. And yes, I have had to go and check on the nights where he has forgotten - thankfully only a couple of times, and never without reason.
Surely it's natural to want to know the people you live with on a day to day basis are okay? Especially late at night.