The Latch app does not store user credentials or information regarding the paired services.
If a device is lost or stolen, an attacker could (avoiding the device security restrictions), access the device and may have access to the Latch app. Even if the user was logged in to Latch, the Latch account information won´t be visible.
The user can login in some other device and reset their password. Resetting the password will terminate the active session in the lost device.
In any case, you can always override the Latch security layer and operate your service in your usual way ignoring the Latch status.