Currently a link from an entity to an area does not allow to enter an alternative name of an area, similar to a "credited as" relationship attribute for a link between a recording and an artist. A possibility to add an alternative name of an area is useful when the area (for example, a city) has been renamed since the event, to show in the link a name of the area as it were when the event happened.

Consider, for example, this artist (poet): https://musicbrainz.org/artist/cb8e21ff-f5ae-4fdb-bd14-72f79b9eb861

He was born in 1718 in Königsberg. The city was known as Königsberg for more than two centuries afterwards, until after the WWII it was annexed by the USSR and renamed to Kaliningrad in 1946.

Although the current name of the city is definitely Kaliningrad, it was known as Königsberg when Leonhard Cochius was born. All biographical sources, including such modern ones as Wikipedia, name "Königsberg" as his city of birth, and it appears to me the right way to reference the city in this particular context.

That is just one example, the same applies to any other case when an area is renamed after the event actually took place.