Unfortunately, in Destiny's case, the content doesn't actually exist anymore. They weren't even able to get the Red War campaign in their defense against a lawsuit -- it's gone gone. It's too late for Destiny, at least insofar as whatever they've already taken out of the game. It's not too late for Destiny to "survive" its EoL date in whatever state it's in once it gets there, but we're not getting anything back that's already gone because the only way Bungie can "restore" it would be to build it all again from scratch.