Why is everyone equating what he said to start with people delaying buying a new system? In the relative past when a new box showed up the following year and change was it for a system and the releases dried up fast within the year or two and even that year was less than when it was alone. If the hardware makers wouldn't flake and keep systems competing against themselves on the market for years plus that wouldn't be an issue. So back to his comment, if a console maker started seeing developers hitting a wall on quality, and they knew tweaks and tricks to maximize some new efforts on the system (much like old PC demo makers did like in the DOS days doing some crazy stuff under big 386/486 restrictions) why the hell not do it? I wouldn't make it a public blow out announcement but there wouldn't be harm in releasing a 2.0 version of the dev kit tools which have those exploits in the manuals. It's really no different than some geniuses figuring it out on their own, making their own tools, or coding in some super optimized code to pull of some magic say like Project S11 on the GBC.
If you as a console maker actually bother to cut the cord within 18mo of the next system arriving, this shouldn't cause a problem with selling new stuff. It could help extend the life of a system longer so you wouldn't so quickly have to replace the hardware maybe giving it an added year or two where things can still feel fairly fresh and there's no harm in that. If the releases dried up and the makers were made to jump to the next system no longer giving out licenses/authorizing more releases it wouldn't harm new generation system sales. You just have to learn some balance and when to cut off the old for the new is all which is what they've forgotten this generation it appears.