The building in that example does have only one address. The old address is not valid any more. People just accept the erroneous use of the old address for the sake of expediency.

It has at least two official addresses each with a [time frame] of official validity.

When merging records the old address, no longer valid with the local land management agency, still appears on old notices and on current state and or federal records (as land naming agencies are layered in some locales with changes taking time to perculate).

The old address is "the correct address" in the context of birth records, old newspaper articles, last years tax records, etc.

You're technically pedantically correct .. but in a manner that's moot when faced with the realities of day to day day reconciliation of meaning of text on an envelope or document.