Putting a dead character in a container and then yeeting that container into a chasm will no longer permanently destroy the character - they will now float around as a resurrectable Soul Echo as expected.

QA clearly wasn't good enough if they didn't pick up on such a game breaking bug prior to release

And...

If you dismiss your companion to camp and shove them into a chasm, Withers will now be able to resurrect them... so you can shove them into a chasm again, probably.

Whoever wrote these notes really deserves some credit