The AVICOT-APP concept is opposite: People would (should) like to know if they represents a danger to, say, their elderly parents, who may die if infected. Thus, there is no need for "the system" to be able to track or identify them at all. Only you, the end user, will ever know if you are in high risk.
> Only you, the end user, will ever know if you are in high risk.
In it's current iteration the protocol you propose contains this:
"3. Regularly, e.g. every 6 hours, the AVICOT-APP checks the public “COVID-19 level 0” list on a WHO-organized AVICOT-SERVER. Entries in this are Bluetooth IDs of devices owned/used by officially diagnosed COVID-19 cases, who have given their consent to this publication. The list may be regionally organized, to limit mobile data requirements."
If it is regionally organized this seems like a technical gimmick. If it has a larger scale, there remain privacy implications that would have to be carefully investigated, even with user consent - which dismisses it completely for any form of rapid deployment. Take the above, you either risk exposing Bluetooth hardware identifiers of those consenting known infected or, rely on me uploading my data to whoever it is that runs this. A better model for that part would be something like what HIBP does for password breaches but my point is that the proposal does not address this and since puts doubt on the "anonymity" part of the title. Even if it did, a large part of HIBP is that I can't control that HIBP has the information in the first place. The submission calls all this "sufficiently anonymous" and I would argue that there is no such thing, especially in this context.
Or point 4. "The server then evaluates the data with an algorithm designed to estimate the infection risk." why? We have people that can do that, more effectively than a hastily written algorithm. This just adds unnecessary fluff. Point 5 is just redundant with point 4.
I have no doubt that this is done with the best intentions in mind but the road to privacy hell is paved with those. We would be better off if we used our collective tech knowledge to build something that makes us more prepared and facilitates collaboration on the authority level for the next time we might need it.