Terms and conditions do not override law. Coerced consent is not consent.
By law, the user experience must not be different based on whether the user has or has not given consent for tracking.
Registration implies consent to process information (identity) for the purposes for which that information was provided, namely access to the content. It does not imply consent to use that information for other purposes such as tracking, and so any attempt to track a user around a site for advertising purposes using their login details would be in breach of the GDPR, unless the user has explicitly and freely given separate consent for that to be done. For that to be possible, the request for consent to track must be completely separate from the process of creating an account or logging in - it cannot be part of the terms and conditions.
By law, the user experience must not be different based on whether the user has or has not given consent for tracking.
Registration implies consent to process information (identity) for the purposes for which that information was provided, namely access to the content. It does not imply consent to use that information for other purposes such as tracking, and so any attempt to track a user around a site for advertising purposes using their login details would be in breach of the GDPR, unless the user has explicitly and freely given separate consent for that to be done. For that to be possible, the request for consent to track must be completely separate from the process of creating an account or logging in - it cannot be part of the terms and conditions.