measureCoaddSources.py writes datasets deepCoadd_meas (catalog of measurements) and deepCoadd_srcMatch (matches between catalog and reference). The naming of the latter appears to be an error during the port of functionality from HSC. In order to make clearer the relationship with the "meas" catalog, it would be better named deepCoadd_measMatch.
This change will affect only what the butler calls the dataset. It should not invalidate any existing files on disk; they will just have to be read by the butler using a different dataset name.