I wonder if the event can be held even though the cosplay is based on the country the characters are originally from?

There is a lot of cosplay of Chinese copyrights, e.g. Genshin Impact, Azur Lane, Arknights, Super Cube [1] as well as mobile games for which I've collected 20+ photo sets that don't seem to have any documentation in the west. South Korean titles like Blue Archive are big.

[1] Not be confused with Super Cub

Notably China is the world center of cosplay so far as I can tell these days.