Event shop hasn't got the flags for Scotland, Finland nor North Macedonia, and maybe others I haven't looked for.
As these teams qualified for the final stages, their flags should be available for purchase.
It's not just for the World Cup (otherwise how do you explain Wales and Albania being available?), the flags have always been updated for the Euros as well when relevant.
(Speaking of flags, the UK one is still upside down on the server lists after 10 years of reminders. )