In ArcCatalog > Create Feature Class > From XY Table, if the projection for the input table is defined as Geographic Coordinate System > North America > "GCS North America 1927.prj" the output shapefile created in the process has the projection defined as
"GCS_Assumed_Geographic_1"
In the Create Feature Class from XY Table dialog, IF the user clicks on the AdvancedGeometrySettings > Edit button for Spatial Reference > Select > Geographic Coordinate Systems > North America, and selects "GCS North American 1927.prj" the output projection definition is correct.This is not necessary for GCS North American 1983, and should not be necessary for 1927 either.