Unicode® ICU 75 updates to CLDR 45 (beta blog) locale data with new locales and various additions and corrections. C++ code now requires C++17 and is being made more robust.
The CLDR MessageFormat 2.0 specification is now in technology preview, together with a corresponding update of the ICU4J (Java) tech preview and a new ICU4C (C++) tech preview.
For details, please see https://icu.unicode.org/download/75.