When the End of Life for Managed and Standard DNS products was announced last year as May 2020, we disabled annual renewals. At this time, we are only accepting renewals for our Standard DNS service on a monthly basis, however with the recent extension of this service, we are in the process of re-enabling the option to renew for longer terms. Please watch your renewal options in the coming months for this update.
With respect to DNS Pro, it is a separate service from Standard and is limited in functionality comparatively. It does not work with personally registered domains, nor does it allow you to add TXT records to it. Based on your use case it would not be recommended.
OCI DNS at present does not feature dynamic DNS and does not work with the Dyn update client.
Oracle + Dyn
Thank you for your response. Sounds like I am out of luck as it relates to getting the same functionality I have today, but at least I have a couple of years to make a change unless Oracle adds a service that is comparable.