This was the last thing I would have expected coming into this topic. As one of the many that were affected by the poor game on launch night and thereafter, I'm listening. If he drops the ball with something distasteful, though, I probably won't buy another MK game ever again (yes, I realized they outsourced the PC port, but they soured the ground).
I would imagine that it would be similar to how it worked with the original game on PS4 and XBone -- everyone gets the patch (so everyone gets the updated netcode and balance changes) and the Kombat Pack 2 can be purchased as a separate DLC pack.
Hopefully they're serious about cleaning up the PC version (the way they handled that was awful), although I can't blame anyone for not getting excited regarding anything WB does on the PC front.