No, it's not a joke, April Fool's or otherwise. It's just the same usual incompetence and website malfunctioning that we see all the time with the rewards program.
So the only way to see what lesson applies to which gift cards is to click on EVERY SINGLE card to see which lesson(s) is/are associated with all the cards...maybe this is intentional, maybe they were trying to change the format to something more difficult but (unsurprisingly) weren't smart enough to pull it off....
Looks like just a bunch of $5 cards anyway for the extra credit this month (much like last month), so not really worth it anyway....unless more extra credit rewards are available but aren't viewable yet due to said incompetence....who knows anymore with this rewards program, not much value nowadays....
And now we also get the added bonus of having some merchants not even being able to process gift cards obtained through AARP. This is not made up folks, I have a case open now with AARP regarding some Burger King cards I *bought* through AARP which are simply not processable at any of BK's restaurants, I've tried...so now we apparently have to be careful with cards we get through AARP because there's no way to tell if they'll be accepted by a merchant or not until you try to use them. Lovely. Great way to run a rewards program.