Well, the privacy policy is taken over from Sitejet Studio where we got Matomo included as an option.
I highly recommend this thread about some more info: Data privacy / Datenschutzerklärung - #2 by Ulf_Siemen
The topic is quite abstract and complicated. I am currently also working on a FAQ to give you a better understanding.
My personal view: In the end, it all got so complicated that I highly recommend a professional consultation for questions and specific tools for Cookie handling.