Users imported by AD Connector will be able to make access to platform regularly, without the need for any changes. In fact it is not the platform to take care of their authentication, but the "Proxy" component of the connector: since these users are "marked" as "imported", the connector will ensure that authentication is demanded to the Active Directory Server.
The scheme is the following :
The login service identifies the username as "imported by AD Connector", then it forwards an authentication request to the connector which in turn asks the AD Server to get the authorization and then forward the response to the login service.
A dutiful clarification is that the "Sync" component of the Connector does not import credentials (users in THRON will not have a password).