Since water and lava are (currently planned to be/in the process of being converted into) fluids, a distinct system from blocks, having them be in the blocks folder is a bit misleading. These should be in dedicated models/fluid/ and textures/fluid/ folders.
Linked issues
relates to 12
MC-212653
Several item models exist in the models/block folder, despite not being block models
Resolved
MC-212740
Textures for empty slots are in the textures/item folder, despite not being actual items
Resolved
MC-200944
Block cracking textures are in the block textures folder, despite not being block textures
Open
MC-200946
Item frame texture/models are in the blocks folders, despite item frames not being a block
Open
MC-271366
Banner textures are not located in an optimal or intuative file path for resource pack creators
Resolved
7 more links
Can confirm.