Thank you for posting this and if it is from a reliable source then you can see that while I never meant to not believe in what you were told previous that Marantz has a new policy to not replace the AK4458 like Denon did, I was simply being skeptical about the different stories told by different people who apparently also go their responses to their enquires from D+M's customer support teams.
Just fyi a couple days ago, I emailed Marantz and requested that they forward my question to their engineering in Japan for further confirmation of which IC they are using, and I cited that their website still are advertising using the AK4458 yet their Japan website says (as linked by bigguyca originally) the SR6015 and the NR1711 as well as the SR8015 were getting it replaced. So I am hoping by confronting them with conflicting information they are still presenting on their websites that they would feel obligated enough to get us the final official answers.