Ah, I see. I overestimated the amount of stripping / anonymization that was being done on device. Thought the server-side could be quite generic. Thanks!

Naturally the server needs to know things.

If you want it to, for example, summarise your HRV or menstrual cycle you can't anonymise it or you don't have any data to analyse. It'd be just "wink wink nudge nudge" with zero context.