No, the "best thing that happened" (in TFA's author's opinion) is that this specific tool exists, with its particular design. Rust is an implementation detail. Most of the benefit that Uv offers over pip, in my analysis, is not a result of being written in Rust.
3.14 is a big deal.
I don't think Rust is incidental here. First, uv's particular design cargo culted from... well cargo. Which, they should be cause cargo is a great tool, no shade there.
But otherwise, people on this forum and elsewhere are praising uv for: speed, single-file executable, stability, and platform compatibility. That's just a summary of the top reasons to write in Rust!
I agree 3.14 is a big deal as far as Python goes, but it doesn't really move the needle for the language toward being able to author apps like uv.