So first obvious caveat is that this is "private" (or at least not worse than BTLE), until the moment you test positive. > At that point all of your BTLE mac addrs over the previous period become linkable.

Linkable over the period of 14 days. Or even linkable during one day - each day means new key, so linking between these might be attempted only on basis on behavioral correlations.

What to do with such data? Microanalysis of customer behaviors? It won't be possible to use such data for future customer profiling, as it won't be possible to match the history with identifiers after the infection. This data is practically worthless.