I'm not sure. I think the OM-D E-M1X is a "halo" project. It shows the best Olympus can do, but will not sell in big numbers. I doubt someone in the market for a OM-D E-M1 Mk II is going to buy a OM-D E-M1X instead. I would imagine they compare the OM-D E-M1 Mk II to offering from Sony, Fuji, Panasonic et al..
Searching on the web I found the OM-D E-M1 came out in October 2013, the Mk II in December 2016, so would suggest the Mk III is due Q4 this year. By that time I would think anyone in the market for the OM-D E-M1X has one, so no risk (however small) of cannibalizing sales.