The news that Ubuntu will drop support for the 32-bit x86 architecture was discussed recently by the Wine developers, on the Wine-devel mailing list. The Wine developers are concerned with this news because many 64-bit Windows applications still use a 32-bit installer, or some 32-bit components.
In practice, the only cases where 64-bit only wine will be useful are when 64-bit applications are packaged some other way (such as a .zip, Steam Play, or packaging specifically for Wine) or for running Wine builtins like msidb. (Vincent Povirk of CodeWeavers)