No. This is in the EU, and specifically Belgium. The claimant's name uses characters that are probably used in French (as French uses diacritics), which is an official language of Belgium.

So I suspect that the ruling really is that the bank should use a system that allows to correctly write the country's official languages, which seems quite reasonable.

Now under EU laws this would probably extend to EU languages, with the likely caveat that, I think, different alphabets are expected to be transliterated into the local one. E.g. Greek names are expected to be transliterated into the latin alphabet in Western Europe.

I am pretty sure that there is no expectation that people can use their names written in, say, Chinese characters as that is not reasonably legible.