Retroactive Pricing - Standard PO Approvals with Inactive Buyers

I have a group who has run into the following scenario and looking for resolution options:

Like many MFG companies, Corporate will establish contract pricing that plants will locally execute against.

There is a Global Blanket Purchase Agreement outstanding. Standard PO's have been created against it for the past year (sometimes longer). Retroactive pricing is a regular occurrence in this industry. The GBPA now has a price update and several of the standard PO's (that were 9 months old in this scenario) are getting updated with new pricing. These PO's have already been received and invoiced so there is no additional activity on them - it is simply a price update that is generating revised journals and invoicing. However, the Buyer assigned to that Standard PO is now inactive so when the retropricing activity happens, these PO's now go into a Requires Reapproval status since there is validation happening and the Buyer is now inactive. We could be talking about 5,