It is of course possible, and I have no specific knowledge for this case. I do have knowledge from the past CPUs I've worked on, and there were many cases where to perform optimally we needed a little tweak to the chipset. Ideally you recognize this early on, and get it in there prior to anything launching. Often you can see such significant changes that you've already got a new socket and support glue planned out long in advance, so it's all good. But... Sometimes you don't see a possible improvement until the previous version is now in the wild, and your intial intent was to just reuse the glue. At that point you face a really hard choice - do you cripple the new product to retain compatibility, or do you make the tweak, knowing it will piss some people off. BELIEVE ME, the big buyers (completely dwarfing the market for home users who want to upgrade) do not want a forced board spin if it can be avoided at all either. The new CPU is what moves boxes, not the chipset. I do not want to sound like an apologist, as I am certainly not. But I would respectfully indicate there is a lot of pressure with considerable leverage to not change the chipset, and if it does, there was likely a good reason.