I guess more user registered here in this forum than the entire population of slovenia. They are creating there own crypto currency and I think till now they do not have their any fiat currency.
I do not read anywhere in this article that they will be using bitcoin in that city. Article says that they will use Elipay.
Did you read the title ? "Slovenia creates first bitcoin city in the world", and of course other cryptocurrencies will be accepted in some stores.