Future-proof is a reasonable goal for a desktop PC, television, digital camera, automobile, wristwatch, or other more mature technology. It's just too soon to expect future-proofing from tablets or phones.
As long as the tablet continues to do what it's supposed to do , it shouldn't really matter that there's a newer OS out there.
As compared to the Kindle fire, which was never any good at doing what it was supposed to do. It wasn't even present-proof.