Did you not read they are elderly indoor cats?
That would be the same as putting your healthy but elderly aunt outside and let her fend for herself.
We get lots of animals dumped on us cuz we’re a farm but most of these critters get killed on the road, starve or predators get them.
Just because Meow Meow catches the odd mouse doesn’t mean she could sustain itself in the outdoors!
Well then have them euthanized. You wanted advice and you didn’t like it. Get off of me.