Yeah, not particularly vested in his comments.
The comments from the id devs are more relevant, because their engines are always pushing envelopes. If they're commenting that the XSS will have RAM issues, I'm more inclined to believe them because id generally delivers cutting edge tech with each release. With that said, Microsoft have bet a lot on their Velocity Architecture, to act as a multiplier on RAM. Microsoft also know their stuff - literally some of the best computer and data science folks on the planet. I'm curious to see how this one actually plays out - did Microsoft get it wrong, or do Dev's just need time to get to grips with the new hardware?