Google announced that it will disable most of its non-core feed management features, including the ability to send email notifications of feed and blog updates on changes to the feed management service’s FeedBurner conversion.
According to Google, Feedburner will transition to a more stable infrastructure from July 2021, and the service itself for all users will continue. However, at the timing of infrastructure migration, most of the non-core feed management functions, including feed email subscriptions, will be discontinued.
Basically, core management functions such as URL, source, feed title, and metadata change are also provided by taking over the existing feed, so most users will not need any additional work. If you switch to a different email subscription service, you may want to do a migration that exports your registrant information to CSV. It will be possible after July 2021, when the infrastructure for exporting registrant information is transitioned.
Google says it’s happy to keep Feedburner up and running through infrastructure migration changes, but it recognizes that the change could mean further work to find an alternative solution, and it says it will notify you early. Related information can be found here.