I work for Fitbit. I don't speak for Fitbit, but the web page you cited does. I don't see any claims to anonymize unshared data. I just see "We may share non-p

I work for Fitbit. I don't speak for Fitbit, but the web page you cited does. I don't see any claims to anonymize unshared data. I just see "We may share non-personal information that is aggregated or de-identified so that it cannot reasonably be used to identify an individual."