Upon calling Diversions arcade at approximately 11:55pm last night, I
was told that they had "just got [MK4] up and running." The gentleman on the other end of the phone also mentioned that they were, in fact, testing the game there. MK4 should show up at Enchanted Castle and Just For Fun today as well, yet there is no concrete evidence that it will. So, if you live in the Chicago area, visit one of these arcades and play to your heart's content. Thanks to
sven for the tip-off