Official comment

We have assurances from PayPal that our PayPal integration is fine, and does not need updating. We clarified that our payment requests to them are fully compatible with their system and there are no issues with it.
In their response, they recommended you reach out to PayPal as to why you are getting the notice:
"Ontraport is not on our list of partners to reach out to regarding this request. This likely did come from one of your merchants as part of the Merchant Org outreach. We suggest the merchant follow the directions provided and open an MTS ticket directly with our technical team.
The link for MTS is below:
https://www.paypal-techsupport.com/
Once on the page at the bottom they can click Contact Support. Here is where they will complete their ticket. It is then assigned to a technical rep on our side who will work with the merchant directly."