I recently tried to use Zarr via the NCZarr code in NetCDF 4.8.1 and it did work in NCDatasets.jl (and quite likely with NetCDF.jl too) without code changes (at least so far) in these packages as the Zarr files can be access with the same NetCDF API. I put some notes here.
As alluded by Fabian the concept of named dimension (central in NetCDF) is handled differently in xarray than NCZarr (https://github.com/zarr-developers/zarr-specs/issues/73 ). Clearly, it would very useful to have named dimension in the Zarr standard (or at least Xarray and NCZarr adopt the same extension: https://github.com/zarr-developers/zarr-specs/issues/41).
In any case, NetCDF 4.8.1 supports also the xarray extension when a user uses the xarray mode.
I am wondering if anybody is interested in the STAC spec (https://stacspec.org/). It allows to make a catalog of data products (quite often stored in GeoTiff or Zarr). It is used in the pangeo community and on the Microsoft’s “planetary computer”. To me, it sounds like a fun community effort to implement this 
.