When we delete or lose access to the user linked to an order approval rule, this order cannot be reprocessed so that a new user can approve the order and with that the order remains pending approval.

• Create an approval rule link to an email
• Create an order that fits the rule created in the previous step
• Delete this email from the store's user base.
• Add a new user to the rule where the deleted user is.

At this point the order will not have its rule updated.

There is no workaround for this scenario;