I think netcdf4 is inflected with GPL code. I'm wondering if it could be made an optional dependency of intake-xarray, or moved into a separate intake-netcdf4 package.
Although conda-forge reports that netcdf4 has an MIT liencse, netcdf4 has a hard dependency on cftime which has a GPL license.
h/t @dylanmcreynolds who noticed this problem.