Brought to my attention in the closely-related MC-248709.

The bug

Falling blocks store information associated with block entities in a field named "TileEntityData". The term "tile entity" is a term which has long since been deprecated (I recall there being a push on the wiki around 2014-15 to replace "tile entity" with "block entity", although I'm not sure if this was due to anything Mojang said; nonetheless, almost all other parts of the game have since deprecated "tile entity" in favor of "block entity"). As such, it still being used in the modern game is an issue, and causes unnecessary confusion.

How to fix

This should be renamed to something along the lines of "BlockEntityData" to eliminate this term.