It’s not like Microsoft has artisanal cartographers sitting around deciding what to call every geographic feature. Bing Maps ingests its base map data from providers, which in turn aggregate a bunch of authoritative, commercial, open, and government datasets.

And for things like official geographic names, government naming databases are often one of the authoritative upstream sources. So if the U.S. government changes the name in its official geographic database, it’s not surprising for that change to eventually propagate through map providers and into Bing.