Axanar is never going to win on the Copyright front. And on the Trademark front their claims are weak weak weak. They are claiming "failure to police". Here's an example of a major brandname in such a situation...
Is Axanar actually saying they plan to raise a trademark defense? Because if they are, then they haven't read the lawsuit. CBS and Paramount did not raise a single trademark claim. This is purely a copyright lawsuit. The trademarks are irrelevant (he says in Borg monotone).
Sorry, I was a tad ambiguous in my pronouns in the post, I edited to make clear the distinctions between Axanar proper and fan arguments.
No idea what they plan, but some people keep claiming "abandonment" as a possible defense for fanfilms, so I figured it was time to clear the air about what that means.