Yes absolutely they can
You know the purpose of this is so they can use them without being tracked though, right? If it’s easy to exclude outliers and bad data, it makes this suggestion pretty useless.
As people have suggested, there’s almost no reason to ever have this data leave your own personal device or network. Women have tracked their periods for thousands, maybe hundreds of thousands of years.
That’s that me. But the company I work for is big enough that if they’re fucked, it looks worse on my bosses for only having one of me and no plan. So fuck that, off I go. I told them how badly things could go if someone grabbed my laptop, so that stays very safely behind too.