Oh dear...

Subject: zlib_1.2.3.3.dfsg-16_amd64.changes REJECTED

Reject Reasons:
lib32z1: lintian output: 'embedded-zlib ./usr/lib32/libz.so.1.2.3.3',
+automatically rejected package.
lib32z1: If you have a good reason, you may override this lintian tag.

I guess I should’ve actually reported the lintian bug rather than just ignoring the bogus warning.