Because you can share things to campaigns, it's possible for you to delete a campaign, and thus, have a bunch of "dangling" campaign references. I.e. references in sharing settings to campaigns that don't exist. In such cases, the references should be deleted.
Sharing integrity remains valid because the user's profile should no longer have the campaign id reference and thus, should not pass any security checkpoints it shouldn't.
Because you can share things to campaigns, it's possible for you to delete a campaign, and thus, have a bunch of "dangling" campaign references. I.e. references in sharing settings to campaigns that don't exist. In such cases, the references should be deleted.
Sharing integrity remains valid because the user's profile should no longer have the campaign id reference and thus, should not pass any security checkpoints it shouldn't.