The whole internet of things idea is just salespeople talking. Unfortunately, managers listen more to salespeople than to engineers, so it may still hold true.
IPv6 is no related to the internet of things. We need IPv6 to have ip addresses enough that everybody can have a PC. And a tablet. And a phone. And right now, there's only about enough for half the people on the planet to get ONE ip address, and that's if every subnet is filled perfectly.
However, because the people behind IPv6 wanted to be absolutely sure never to run out again (even after we colonize Mars), they made IPv6 large enough that even if the "internet of things" morons get what they want, IP addresses is not going to be our problem. Keeping all those "things" updated and secure is.