That is not true at all ... I used to have 2 tomcats and they would be out all night. When I got up in the morning I would find a couple of dead voles or mice on my doormat because they had been hunting all night.
That's quite surprising because my neutered tom sleeps on my bed all night and he's never caught as much as a moth.
Females tend to hunt more than males, in my experience - I think it's instinctive behaviour in that in the wild they obviously need to hunt but they also need to teach their offspring these essential skills. At the moment, both my females are spending a lot of time outdoors, one of them even brought in a live mouse at 3am the other morning (rescued) but my dopey male won't go further than the back garden.
As for your response to the OP, howling at night is a well recognised phenomenon in older cats. As I said, they can get confused and distressed when they wake in the dark and often just need comfort and reassurance. It doesn't necessarily mean anything is physically wrong but it's always best to get cats vet checked to be on the safe side - which the OP is doing and I am sure she will update us in due course.