Blockstate files now exist for air, cave_air, void_air; however these blocks cannot be given any model.
Barrier, structure_void and light ones are used for the breaking particle and the "block_marker" particle. Air and its variants don't have these.
Comments 10
The files are used to select the particle for all the special rendering blocks (blocks with no model, and blocks with entity models).
The only ones this is valid for is air and it's variants.
Yes, but I now excluded structure void, and barrier because the particle usage for "block_marker" depends on the block state, so it is only possible for light to show the right number with this. Having those 2 be inconsistent with light would be weird. Air variants are still listed.
Confirmed for 1.13-pre4. The game will also generate model files now too, which are empty, unless that was already the case, and not marked in the report.