They are unlikely to terminate the life memberships unless they are doing away with the whole Admirals Club program, are taken over by another airline, or some other similar dire reason. This just means they don't have to worry about pro-rating refunds if such an unexpected event occurs very far (15 years or more) into the future.
It AA actually already intends to discontinue the life memberships in 2020, and is merely using "lifetime" as an expedient to deceive customers, there would surely other legal remedies available, such as fraud in the inducement or illusory contracts, etc., should they actually execute such a dastardly scheme. If you distrust AA that much, why would you even be in their frequent flyer program?
By the foregoing, I am not undertaking to provide legal advice to any reader of this thread. As with all important financial decisions, consult with your own legal and financial advisors.
Has anyone reading this thread bought one?
Come on, don't be shy!
My wife and I bought spousal life memberships in the Continental Presidents Club and US Airways Club in 1999. The latter is no longer offered.