Slack API manifest api_groups version transition and backward compatibility

An integration declares compatibility via the app manifest api_groups and relies on Slack's documented versioning and compatibility window for schema stability.

The goal is to understand whether a schema change applied to a workspace can be rolled back safely without breaking existing calls that depend on the previously declared api_groups version. The documented behavior is that schema changes roll out gradually and older versions remain accessible per the app's declared compatibility window, with experimental features opt-in.

Uncertainty remains around the compatibility boundary. The documented boundary does not guarantee atomic rollback of schema changes, and behavior depends on whether the change is additive, deprecated, or breaking, as well as workspace-level admin settings. Version availability windows are not publicly documented and may change without notice, and behavior differs between Free, Pro, and Enterprise Grid plans.

Questions:

• What conditions determine whether an older API version remains accessible after a schema change is enabled in a workspace?
• Does the manifest-declared api_groups version remain callable for the declared compatibility window across all plans?
• How do workspace-level admin settings affect fallback behavior for deprecated fields after a schema change?