iTunes will convert WMA format files to M4A automatically upon import file/folder. So don't worry about it.

For the record, Wave files can have various codecs defined, but the format lacks metatags for describing the content that deprecates the file format.

Originally MP3 had no tags, but someone developed a solution, and gave it away and it was quickly adopted. Later enhancements were added to extend the capability. MS seems to be indifferent to fixing WAV files so the wheels get reinvented over and over again.