On the attached file you can see what was sent to customers in March 2025.

There has been some confusion about what is happening to customer instances when the upgrade to the Australia release. The concern is that a customer might find all of their dashboards and reports from the legacy reporting system. You'll hear other names like Core UI reporting, Responsive Canvas dashboards, the old dashboards, etc. For this purpose we'll just call it "legacy" reporting and analytics.

Quick summary: There is no mandatory migration at any time. But support for legacy PA content will end with Australia upgrade.

As of Australia customers must use Platform Analytics to create any new content. However, legacy dashboards and reports will be available to run/use indefinitely. As of Australia, the legacy dashboards and reports are not supported other than critical security issues.

For those still not sure, you are using the legacy system if your report editing screen looks like this: