I have two (2) identical feature classes, one is in NAD_1983_StatePlane_New_York_West_FIPS_3103_Feet and one in GCS_WGS_1984. In ArcMap desktop with NO geographic coordinate system transformation assigned to my .MXD, the points line up perfectly on top of each other. When I publish the two (2) feature classes up to ArcGIS.com there is a three foot shift between all of the points. I can replicate the ArcGIS.com shift I am seeing in desktop by assigning the NAD_1983_To_WGS_1984_5 geographic coordinate system transformation.
So my question: Does ArcGIS.com automatically apply the NAD_1983_To_WGS_1984_5 geographic coordinate system transformation when you publish a feature class that starts in NAD_1983?