Hello Gene,

Please see the post below on a way to get back and to have Performance Analytics/Reporting reinstated. Unfortunately all dashboards inactivated will remain inactive after this move back so you will need to re-activate dashboards.

https://www.servicenow.com/community/performance-analytics-blog/platform-analytics-migration-what-is...

I don't have the information at my finger tips on Upgrade Plans and this migration.