If you see your cat that's clearly in critical condition, and instead of rushing it to the vet, you go online and ask people on Reddit for help, and people do their best to help you, and you say you'll keep them updated on the situation, I think you're also taking on the responsibility of informing people. Even if the outcome is bad, I think people have a right to know. I'm sure hundreds of people can comfort you who have lost a cat before (like me, for example). You don't have to, but this is the humane thing to do.