Hi @renan.padilha,
Welcome to the Auth0 Community!
Yes, your findings are correct. We currently do not support retrieving a new access token with a new org when using the getAccessTokenSilently() method.
If this is needed, you could try logging the the user against the other organization with either the loginWithRedirect or loginWithPopup methods and specifying the organization as a query parameter.
Let me know if you have any issues with this.
Thanks,
Rueben