Never heard it directed towards Cats Myself ? Most cats prefer to Kill thier own Dinner...........at least that's my understanding.
As far as Bears go yes seems to be lots of "Dinner Bell" supporters however I'd suspect this behavior to be "a rarity" at best.
Any bear that "attends" the scene of a Kill was likely in the immediate area already and is/was more then likely attracted by the smells of the same then the report from the rifle.....
Not saying it can't or does not happen but again it's certainly a rarity when one considers how many bear, moose, elk, sheep, deer etc. are shot in BC every season and certainly a Bear did not come racing to every Kill
I'd suggest you enjoy your Hunt for ???? and not worry too much about Bears....use your head when in Bear country but it's certainly not something to be paranoid about.
But that's just my Oppinion