TLKS instantiation differences between data types and data family declarations

The following works on the wip/top-level-kind-signatures branch:

type T :: Type -> Type
data family T

But if we change T to a data type:

type T :: Type -> Type
data T

Then GHC complains:

[1 of 1] Compiling Bug              ( Bug.hs, Bug.o )

Bug.hs:8:1: error:
    • Expected a type, but found something with kind ‘* -> *’
    • In the data type declaration for ‘T’
  |
8 | data T
  | ^^^^^^

This is a bit confusing, as I would have expected the treatment of data types and data family declarations to be similar here.