Request pick up notice not sent to requester when requester's barcode has been changed after request was created

Update:  Approved as R1 2021 Hot Fix #1 if Chalmers fall semester starts before September 1. Please see Marie's comment below as they will not be updated to Juniper before their fall semester begins so a Hotfix is required.

Overview: No request pick up notice is sent (or even generated?) to the requester if the requester's user barcode has been changed after the request was created. 

Originally reported in: Chalmers Honeysuckle, verified in https://folio-snapshot.dev.folio.org/ 2021-04-23.
Reporting library priority: Important. This is a bug that affects patrons directly.

 
Preconditions:

A notice policy set to send Pick up notices when a request gets status Open - Awaiting pickup. 

Steps to Reproduce:

1. Go to the Requests app, and create a request for user 12345
2. Got to the Check in app, and check the item in
3. Go to the Circulation log, and verify that a Pick up notice has been sent to user 12345. The notice has been sent.
4. Make a GET request to okapi-url/email to verify that a Pick up notice has been delivered to user 12345. The email has been delivered.
5. Cancel the request
6. Go to the Requests app, and create a new request for user 12345
7. Go to the Users app, and change the user's barcode to to 12345edit
8. Got to the Check in app, and check the item in
    

Expected Results:

Go to the Circulation log, and verify that a Pick up notice has been sent to user 12345edit. The notice has been sent.

Make a GET request to okapi-url/email to verify that a Pick up notice has been delivered to user 12345edit. The email has been delivered.

Actual Results:

Go to the Circulation log to verify that a Pick up notice has been sent to user 12345. No Pick up notice is displayed in the circulation log.

Make a GET request to okapi-url/email to verify that a Pick up notice has been delivered to user 12345edit. There is no pickup email for this request, neither delivered or failed.

Additional Information:
I know that the fact that the original barcode of the requester is saved in the request object, and not updated by subsequent edits to the user, has previously caused problems. Linking those issues in case there is a link. Also attaching a file with objects from request-storage showing how obsolete user data is saved in the request.

URL: https://folio-snapshot.dev.folio.org/
Interested parties:
MarieWi