Re missing Japan update :
“Support (Microsoft Flight Simulator)
Aug 9, 2021, 14:56 GMT+2
Hi gspeirs
It seems you were missing a few entitlements.
The entitlements have been manually redeemed on your account, and the package should now be available to download and install.”
Seems this is a common problem and some poor sod is having to go through tons of accounts manually flagging them for the bugged downloads.