The Azure ShareGate migration app requires consent to a new set of permissions for the migration tool version 17.3 and above and the latest iteration of Cloud copy.
The Azure app adds a few permissions required to provide chat migrations for Microsoft Teams.
If you do not consent to the new version of the Azure app, the permissions of the previous version will still be effective. However, you will experience some limitations from the limited set of delegated permissions.
For more information on the delegated and application permissions used by the Azure ShareGate migration tool app, see Which permissions does the Azure ShareGate migration tool application need?
Note: You might have two versions of the Azure app installed. It will not affect your experience to have both Azure apps. If you want to remove the old app, see How do I remove the Azure ShareGate migration tool app?