In the @minecraft/server module, the Block class supports a localizationKey property intended to be used for displaying localized text to players using raw text. Unfortunately, this property does not respect the minecraft:display_name block component, which results in localization attempts being invalid.

Demonstration

Below shows (correct) information about a Vanilla block as reported by scripting:

The following shows (correct) localization of a custom block without the display name component:

Finally, here is (incorrect) localization information for a custom block with the display name component:

This custom block had used "minecraft:display_name": "a.b.c.d", which was not shown by scripting.

Reproduction

This example is taken from the behavior pack in the following world attached for convenience:

This world can be opened (in Minecraft Preview) for inspection or unzipped to access the code associated with such. Interacting with the blocks will send messages like shown above.