This is a request for a policy change.

RFC 4880 (section 5.2.3.23) states that:

If a key has been revoked because of a compromise, all signatures
created by that key are suspect. However, if it was merely
superseded or retired, old signatures are still valid.

The RFC does not specify what to do with a revocation with a reason that is
unspecified.

gpg seems to treat a revocation for an unspecified reason the same way that it
treats a revocation for the reason of being superseded (in other words, past
signatures are still valid).

However, there are compelling arguments for treating a revocation for an
unspecified reason in the most conservative way possible.

• when in doubt it is safer to give a false negative than a false positive.
• people may be hesitant to publicly admit that their key has been compromised.
• revoking a key gives the impression that the key will no longer be valid -

period. The ability to enable past signatures to continue to be valid is a
feature that should require an extra step by the user to specify.