You can see all the version differences here :

https://www.speedrun.com/sms/guide/o7a51

And it is very easy to softmod a Wii and bypass the region lock to be able to read discs from any region.

This has been happening to a lot of people on the Switch version, idk if anyone really knows why and how it works exactly. I know it used to happen on Dolphin You can see a bunch of clips here https://pastebin.com/QQ5Ekysg