No, like FNF Sky, sky dies in the FNF world but some mods and her creator revive her but just in alternate universe, if the creator revive him in reality it would be stupid and just makes a paradox

But the creator can also revive them on their reality

Even the creator revive him/her, he/she still dies in the community or the reality of they're world.

But thinking about it... Every Oc is immortal if he/she dies, the creator can just revive him/her back

Luke : I'm not scared tho. I ate all my bullies in school when I was at highschool :]