TC 11.03 only showed the extension asigned to the Total7zip plugin, not the plugin file total7zip.wcx itself in the properties dialog.and certainly previous versions (or maybe betas) of TC had shown Total7zip.wcx64
Even in 64bit TC the names of 64bit plugins are always shown without 64 at the end of the extension, and they are by default installed in the [*Plugins] sections without the 64 extension. Only a very few plugins are installed with the 64 extension, and only plugins that don't have a 32bit version - Total7zip is not one of them.