ah nice catch - I thought this was a new utility but you're totally right! It appears in the documentation in earlier versions. I edited my comment to remove the just released 😉

Hi @Enrico Parisi, 

I believe that it is "referenced" in the Healthcare Mirroring documentation under Mirroring the HSSYS Database:

The HSSYS Mirroring Utility can automatically perform HSSYS mirroring and validation. It also schedules the Mirror Monitor Agent.

The utility can be downloaded, installed, and supported on systems 2021.1 and later so it is not strictly related to upgrading IRIS For Health.

If the question is whether a better "home" for the HSSYS Mirroring Utility page would be in the "High Availability Guide" under "Mirroring and High Availability" 

Then the answer is perhaps. There is specific upgrade configurations Offline Validation and Mirroring which I assume is the reason it was placed under upgrade reference - though I would lean to agreeing with you that a better place would be under Healthcare Mirroring. 

The documentation team is always looking for feedback (blue button on the right side of any documentation page) - so they would be happy to hear your suggestion. 

check out the HSSYS Mirroring Utility that lets you skip steps 4-9!