Why doesn't custom rpm upgrade replace config files if older release config files are no longer marked %config?

Issue

• If the custom rpm test-1.0-1.el6.x86_64.rpm deploys a file /a.sql which is a config file and if it's updated version test-1.0-2.el6.x86_64.rpm no longer considers /a.sql as configuration file, still upgrade from test-1.0-1 to test 1.0-2 doesn't replace modified version of /a.sql which it should.