The admonition at the top:

  Currently, the default build backend for uv init is hatchling. This will change to uv in a future version.

makes it seem like it's not yet stable, or at least feels like they're still not encouraging it.

I'm quoting Charlie, the creator of uv https://bsky.app/profile/crmarsh.com/post/3lszmqo27b224

Ah, great. Thanks for the reference.

My pleasure!

We consider it a breaking change to switch the default, so that's coming a bit later.