A single alphabet of a single language is actually a pretty useless for anything else than simple testing like "could this string of characters be a native word in that language". As an example, 'c' is not part of the Finnish language since no native Finnish word uses it, but as soon as one starts to use loanwords, or people's names, one will need to use 'c'. Neither are accented letters part of the Finnish alphabet (the umlauted a and o that we have are not accents at all), but the same goes for them too: if there's a name/loanword that has diacritics, we'll use them. So I'm all for rather sticking with 'Latin script' which would contain all the Latin letters, without and with diacritics.