Re: Should result in summary judgement...
The exception clause applies to the relationship between the owner of the data and the entity providing a service to the data owner.
In other words, if I apply to a bank for credit they can acquire, store and retain data necessary for the provision of that credit. If that bank has a separate contract with an advertiser to provide email addresses of anyone applying for credit then the necessity exception doesn't apply there. And contract terms can never override law. Any term in the bank to advertiser contract that breaks the law becomes void.
So a registrar can collect data necessary for the provision of service to the end user but their contract to publish that data in whois is void as it compels them to break the law. That is exactly the position of EPGA and I would be very surprised if they do not prevail.
If ICANN are pressing ahead with this challenge then one of two things has happened. Their lawyers know it will fail but they get paid anyway so what the hell, lets bilk our client (likely), or their lawyers think the law is worded sloppily and they can twist it to cover the third party contract which was actually what you were hinting it. That is less likely but still possible.