Honestly, if making such announcements is enough to weed out the old and grumpy (and not-so-clever) users... You should make more announcements like this one!
But anyway, it's ultimately their loss. Let them wallow in their own self-righteousness. We like laughing and don't need party poopers!
My own reaction was: "Well, my Pentium M laptop is so damn old anyway," thinking this was about hardware limited to 32 bit. But when I read about ARM being the future, I was like: I've now spent half the weekend thinking about how closed the ARM scene is compared to the x86 scene. There's no way that is possible, especially on an April Fool's Day.