It won't be lower, not a chance. I was quoted 16gb, bit it could be 16gb with extra for the os ON TOP, not included Like MS did. but the speed I was quoted at was lower than SX at 512, and I don't know about that...?
BUT...
The SSDS in these systems change the playing rules, and you no longer need massive amounts of fast memory, because it's just not needed. No game scene I have ever done, including working with ray tracing, has ever gone this high with current in scene vram usage, and as such that's what people are forgetting. You're not going to be loading a whole scene into memory, but what is needed as it's needed. And as such, the lower than expected ram setups are actually fine.
Still hope SX bumps it to 16 full without OS though, but because it's too fucking weird a number for me to focus on lol.