Screenrant reports the law firm announcing the case:
http://screenrant.com/star-trek-axanar-lawsuit-defense-paramount-cbs/
note, it says "has engaged". No indication about the pro bono part. The rest of the screenrant text qualifies as a rant.
press release text:
Valencia, CA-based Axanar Productions has engaged Winston & Strawn as legal counsel to help defend it against claims made by Paramount Pictures and CBS Studios, Inc.
Alec Peters, Executive Producer of AXANAR, a feature-length film financed through crowd funding and direct donations from fans, announced today that the company producing the film, Axanar Productions, has engaged Winston & Strawn, one of the leading IP practices in the country, to provide legal counsel in its lawsuit with CBS Studios, Inc. and Paramount Pictures Corporation. Representing Axanar Productions and Peters will be attorneys Erin Ranahan and Andrew Jick from the firm’s Los Angeles office.