The Square Enix European Store has recently removed all of the Kingdom Hearts merchandise previously available on their digital storefront. The only viewable Kingdom Hearts products are standard physical releases of the games and limited editions, such as the Kingdom Hearts III Deluxe Edition.
Plushies, keychains, pins, and much more have vanished from the site. The Square Enix North American store has been untouched, with all products remaining as they always have been. Other franchises such as NieR and Final Fantasy still have their merchandise present on the European store, so this merchandise removal seems exclusive to Kingdom Hearts.
It is currently unknown if this is solely a mishap on their front or if some restructuring is taking place to remove Kingdom Hearts merchandise from the European store. For now, we will keep our eyes and ears open and keep you all updated.