I think it's hit or miss, I had an order of live rock that had dead corals on it, some came back some didn't.I actually wonder about discarding any?
Had an acro years ago, when I shouldn't have bought any, just wasn't ready for sticks. It died and I left it where it was puttied as I didn't feel like prying off the rock. A couple years later, there was actually new growth from the dead skeleton. Unfortunately have no pics of that.
As for LPS, have a fungia plate right now that had a hammer fall on it overnight. Pretty much died off. Algae all over skeleton. Has started to grow back in the center, plus a bunch of little stalks on the outskirts. When those little stalks grow baby fungia plates about the size of a dime, I break them off and it grows another plate
With those couple of incidents, actually have wondered if just about any coral could regenerate if given enough time and proper conditions to thrive?
Nothing to loose though, if it isn't in the way, leave it and maybe get a nice surprise one day.