The shape argument in empty_like (and counterparts: full_like, ones_like and zeros_like) is important to guarantee functions that depend on creation of such arrays (without _like) to work correctly with the introduction of NEP-18 and _meta in Dask arrays. The argument was introduced by numpy/numpy#13046.

An example where we need such functionality is the moment function, creating both ones and zeros, also with non-default chunks: