The spec currently says:

NOTE: While implementations may choose different values, the recommended upper bound is 8GiB and the recommended lower bound is 0.25GiB (or 256MiB).

8GiB is the bare minimum for many AI applications, so knowing if a device has actually just 8GiB of RAM or more makes a huge difference. The meaningful values I heard when discussing this with engineering were 16, 32, and 64 GiB.

The current lower bound of 0.25GiB has become a tracking vector in itself. It would likely make sense to adjust to 2GiB as the lower bound as even low-end devices have caught up.