Maybe that's why the 512GB RAM models are gone: they opt to pull a model without further announcement rather than increase its prices.
I suspect the opposite. 512gb of LPDDR5X is enough memory to make sixty four Macbook Neos. Apple's HPC/server audience is not very large or demanding, it seems likely that they will avoid memory upgrades during the shortage to focus on delivering value to low-end consumers and driving service sales.