Another option would be to create a python add-in extension for this that runs (when the extension is enabled) when a certain map document is opened calling the openDocument() function which has the Make XY Layer method/logic that @Geo.Dude suggested. Each time the user opens a predefined (saved) map doc that has has a certain name (eg. map doc name "makeXY") it will check for this map name and if found will call the "make xy point" method within the openDocument() function. For a python add-in tutorial of how to create this extension see:
Creating a Python add-in application extension
Here is a class example with the map name check:
"""Implementation for test2_addin.extension2 (Extension)"""
# For performance considerations, please remove all unused methods in this class.
self.enabled = True
mxd = arcpy.mapping.MapDocument("CURRENT")
mapPath = mxd.filePath
fileName = os.path.basename(mapPath)
if fileName == 'makeXY.mxd':
# put Make XY Layer method/logic here