Gonna do 4 millions FW worldwide, for sure.This is the most hyped KH ever, in my opinion.Not only that, but the popular disney worlds there will help it sell outside the fanbase.
Honestly, this game will sell at least 10 millions LT.
FFXV 24-hour shipments+Digital = 5m.
Current LTD = 8.4m(PC/PS4/XB1).
I don't think 10m is realistic for a single player JRPG if FFXV is struggling to reach that sales number. This isn't the same as MHW situation where the potential of sales was held back by the hardware and region, multiplayer focused games tend to do better in the west.
KH3 isn't going to outsell FFXV and nowhere near MHW numbers.