Because “International Organization for Standardization” would have different acronyms in different languages (IOS in English, OIN in French for Organisation internationale de normalisation), its founders opted for the short form “ISO”. The story goes that ISO is derived from the Greek word “isos”, meaning equal.
Whatever the country, whatever the language, we are always ISO.
The compromise that emerged was UTC, which conforms to the pattern for the abbreviations of the variants of Universal Time (UT0, UT1, UT2, UT1R, etc.).
It’s still just Coordinated Universal Time / Temps Universel Coordonné. The “acronym” (really an initialism) does not correspond to the name in either language, other than it has the same first letters.