Connectors when the app changes
Organization → Connectors folds the provider’s own app into the connector’s row with Own app… (Client ID and a write-only secret), and accounts the connector no longer recognizes are deleted on their own and the connector goes back to Connect in Customize → Connectors → Yours.
When the app or the connector’s address changes, the connector is set up again and each person reconnects once.
More in Managing connectors.