The Teams Manager can only send information to users in the tenant who have previously interacted with it. The Teams Manager does not read all users in the tenant but receives the information of a user when he interacts with the Teams Manager. A list entry is made in the Teams Manager database in which the user language is also stored.
Option 1 (roll out)
This can be automatically populated when Teams Manager is rolled out to all users via a policy in the Teams Admin Center.
Option 2 (pin to channel)
If the first variant does not invite all users, you can still add the Teams Manager as a tab in a team in which all users are located. This will force an initial interaction with the Teams Manager without the user having to initiate it himself.