Perhaps, but if the exploit code is published folks can double-check that they implemented the mitigations properly.

If there's no PoC, how can you really be sure?

Why not? There has already been a working exploit floating around, at least now it comes from an authoritative source.

anyone who will use the exploit maliciously will immediately and trivially be able to create a working exploit.

An exploit was already published.

The third party posted an exploit.