History suggests that framework will prioritize allowing memory module re-use for people upgrading from old platforms over performance; see the decision to use ddr4 on 12th and 13th Gen Intel boards when the memory controller supported both ddr4 and ddr5. The igpu on those platforms could have been much faster with ddr5-5600.
If I was betting, I’d guess we don’t see framework consider this until they’re shipping an SOC that doesn’t support DDR5.