Hi @jmort ,
yes, this is a recent change: we have removed the ability for customers to disable apps in Jira and Confluence Cloud, and we have updated the product documentation to reflect this.
For developers of Connect apps though, the API has not changed, and no changes are planned at this time. The enabled and disabled lifecycle callbacks are still fired.
Installations of your app can still be found in either enabled or disabled state. Disabled installations can still transition to being enabled, whereas installations transitioning from enabled to disabled would be out of the ordinary.