The problem is that "common sense" is not a quantifiable standard in law and the ARRL is all too likely to have a differing opinion before the Court. What argument might the Court cite in a concurring opinion? That's up to the argumentation and rhetoric used before the Judge/Magistrate hearing the case.
There are three types of class action suits in State Courts and Federal Court. The first is employment wage and benefits - clearly not applicable here since we are not employed by ARRL. The second is based in product liability - think of the Ford Pinto, Takata airbags, etc. The third and final one is consumer claims - did the buying consumer get what they contracted and paid for? This final one might be the likely actionable justification for bringing an action against the ARRL.
Another question that needs to be addressed is where to file - State or Federal. Since 'diversity' exists throughout ARRL membership... Federal would be a better venue. Diversity among class action members doesn't mean what many might believe it to be - it [diversity] describes where members of the class action reside and where they claim residence. Members may have a single residence or live in multiple states, but the Federal filing covers them all without trying to research civil class action rules of all 50 states and however many Federal territories are involved. Some are Life members, some are annual members, others are multi-year members and they would all have to be certified as members by the respective Court or Courts.
The ARRL is a 501.c.3 organization under applicable IRS rules and is considered a non-profit, so there may be a question as to how much responsibility that an annual, multi-year, or life member has in Board decisions and how much the recent member survey had/has in publishing a physical copy of QST [or other] magazine for each regular [not associate] member. The Court will also have to determine if there is a contractual obligation on ARRL in providing a magazine as part of membership.
Important - I am not an attorney, not a lawyer, or other legal advocate, but am simply bringing facts to consider that have to be considered if someone or collection of persons considers action before the judicial system.