Can i buy splatoon 2 in a diffrent region?

I brougt splatoon 2 european edition in a cash shop instead of Australia. My question is if i buy splatoons 2 expansion on the european eshop after changing my region can i and will it stay in my purchases when i switch back to Australia? Like it will be in my purchase history and i can redownload from the aud eshop? Or will it only be avaliable from the european eshop?

It will be more expensive to buy the euro expansion but i was hoping other then that i can keep downloading it from the australian eshop?