Similar to this question except this is specifically for files that are owned by an organization because they exist in a Shared Drive. Since these files aren’t owned by any individual user, there is no need for them to be assigned to any specific user if the creating user is deleted. They continue to exist and belong to the organization which is in fact one of the original selling points back from when Shared Drives were called Team Drives.
Notifications for things like suggested edits are sent to the e-mail address of the creator of the file. But what happens if that user is deleted? To whom are notifications sent? I’ve looked in the Admin console and I don’t see any options to change who gets notified. So far we’ve not had the need to delete any users (and this isn’t something that we can just test without disrupting things) but we need to plan for this contingency as we rely on these notifications for part of our ISO-9001 compliance.