This is a teory that i made when i was hatching some boxes on my egg hunt. When do you search for the ivs on the pc, you are able to know if a egg have that iv:
Having this on mind, if do you search on the same tool your shinies, i think that you be able to know if any egg have a shiny inside:
Its possible to test this. If someone actualy is doing a shiny breed, put the egg on box and try to search your shinies, if happen the same thing that happen on ivs .. Well the title of this topic is self explanatory ;D .