Fine.
I really don't see why retaining other privileges of membership in the academy is relevant. Consider a company that wanted to diminish the influence of Jains (to take an uncontroversial group since this audience appears completely unable to separate object-level preferences from meta-level principles) on their votes to determine company strategy and retain CEOs or whatnot. Jains frequently wear turbans, though not all do, with other groups using them infrequently or not at all, so they pass a measure saying anyone who wears turbans on more than half the days of the year loses their voting rights. Jains still retain the ability to buy and sell shares and make money off of the stock. Still religious discrimination, no?
Perhaps there really isn't anti-elderly bias going on here. Maybe they really do want to limit the ability of people who are out of touch with the modern film industry to not have undue influence over their awards. But if this were the case, how is this supposed to help solve discrimination? The academy's messaging only makes sense if you buy that 1.) old people are racist 2.) This measure prevents old people from having as much influence as they did in the past and 3.) therefore the academy awards will be less racist now.
To sum up, in general under American jurisprudence a measure falls afoul of anti-discrimination statutes when:
1.) The measure has a disproportionate impact on a protected group.
2.) The measure is adopted with the goal of disproportionately impacting that protected group.
To prove the case:
1.) Age is a protected group, and I think most people of good faith would in any case agree that it shouldn't be a valid basis of discrimination. I don't think anyone can deny that a measure that targets retired people has a disproportionate impact on the elderly (or the disabled, for that matter).
2.) Is more debateable. Though again, without the old people are racist -> this gets rid of old people -> therefore our awards will be less racist the messaging of the academy makes no sense.
Or, DryEyeRelief did some of my work for me, and collected much of the ageism expressed in this thread here:
http://www.neogaf.com/forum/showpost.php?p=193134342&postcount=133
And honestly if you don't think similar thoughts are going through the heads of the people who adopted the measure I'm not sure you're engaging in this argument in good faith.