TIS-B anonymous address
My question was due to the confusing mention of ADS-B in what was supposed to be either TIS-B or ADS-R.

I've now confirmed that the text on ICAO Doc 9871 Version 2 I quoted was due to a error.

In fact DO-260B, and even Doc 9871 Version 2 at table C-37 specify that TIS-B CF=4 is "Fine TIS-B message, AA field contains a 24-bit anonymous aircraft address".

ICAO e-mailed me confirming that this has been fixed into their working document.