Often though, when no attention is paid, assumptions could cause havoc - and I do not want to assume that any language (or region/country) automatically could replace other’s.
You make good points in your comment, but in the case of standard Swedish and Finnish keyboards I think there’s no danger of replacing anything. Finland has two national and official languages: Finnish and Swedish. The letters in the alphabet are the same in both languages, and users of both languages use the same keyboard layout. If you are a Finn, either Finnish speaking or Swedish speaking, you use exactly the same keyboard. They don’t sell different keyboards for the Swedish speaking people in Finland, neither do Swedish speaking Finns order their keyboards from Sweden. The two languages are very different, but as I said, they use exactly the same alphabet.
Here’s more visual confirmation about the matter (from Keyshorts.com). The Finnish keyboard layout:
https://cdn.shopify.com/s/files/1/0810/3669/files/finnish-windows-keyboard-layout-keyshorts_1024x1024.png?3916
The Swedish keyboard layout:
https://cdn.shopify.com/s/files/1/0810/3669/files/swedish-windows-keyboard-layout-keyshorts_1024x1024.png?3916
The situation is different between Sweden, Denmark and Norway. Their languages are very close, but because their alphabet differ slightly, they also have a little different keyboard layouts. The differences are minimal, though. You can easily use any of those keyboards if you can use one. Here’s the standard Danish layout for comparison:
And if it’s the “Finnish multilingual” version you linked, I’d be all for it - it’s usable (and active now) and does not lack keys like the Swedish one.
“Finnish multilingual” is not a different keyboard, but a character layout standard. What you saw are not additional keys, but just additional characters printed to some of the same old keycaps to help your memory. Because “Finnish multilingual” is a software thing, you don’t have to buy a new keyboard, but just change a setting in your computer (if your operating system supports it – new Linux distributions do, but I don’t know about Windows (you may have to install a file)). The standard doesn’t alter anything that’s in the older, more concise standard, but adds easier ways (using Alt Gr key) to type some punctuation marks and a few characters in the minority languages of Finland and other European languages. The additional printed characters on the keycaps are of course handy, especially if you often need to write languages other than Finnish, Swedish or English. “Finnish multilingual” is (unsurprisingly) a Finnish standard (SFS 5966), but because Swedish is an official language in Finland, the standard is of course fully compliant with writing Swedish. I don’t know if there’s a similar standard in Sweden, but if there isn’t, I’d think many Swedes might find this Finnish standard useful, especially combined with a keyboard that has the additional markings printed on the keycaps.
I think the idea of changeable keycaps is very good.