I think "outdated" was a poor choice of words. It is a failure to meet application requirements, which has more to do with design than age. Every standardized UUID is expressly prohibited in some application contexts due to material deficiencies, including v4. That includes newer standards like v7 and v8.

In practice, most orgs with sufficiently large and complex data models use the term "UUID" to mean a pure 128-bit value that makes no reference to the UUID standard. It is not difficult to find yourself with a set of application requirements that cannot be satisfied with a standardized UUID.

The sophistication of our use case scenarios for UUIDs exceeds their original design assumptions. They don't readily support every operation you might want to do on a UUID.