Naming rules within the updates directory are currently:
"It contains one file per quarter year, named [1-4]Q-[YYYY] for the first to fourth quarter of a given year, for example 1Q-2004 or 3Q-2006."
This is rather strict and won't allow to change to a different (e.g., monthly or yearly) naming scheme. Also, I don't see why we would need that restriction in the spec.
Therefore, I'd suggest to update the rules for EAPI 8, along these lines:
"All files in this directory will be processed, unless their name begins with a dot. Any subdirectories will be ignored."