UPDATE
When sending a GDPR “TEST” to myself (via the designated button that shows up in the “People” menu when there is 1 or more unconfirmed GDPR records), the correct email template is sent. Additionally, if you click the “send GDPR email to everyone who isn’t confirmed already” – it will also send the correct template.
So it is only when the system automatically generates the initial GDPR confirmation email as a result of registration that it is somehow reverting to the original plugin text. Hopefully this will help narrow down the issue.