In GLEP 60, MISC manifest entries inherit from the abstract _INFO type, which is defined as follows:
_INFO (new, abstract)
This is the functionality of the old AUX, but does not include the implicit 'files/' prefix in the path, and is verified relative to the working directory instead of $FILESDIR.
The modification or absence of a file listed as a _INFO-derived type is not an error unless the package manager is attempting to be strict.
We can add a repos.conf setting to control this strict behavior (the [DEFAULT] section can be used for global settings).
I've posted a patch for review:
This is in the master branch:
Fixed in portage-2.3.3.