Tracking internal uses of concat that don't allow setting all the kwargs #10095
Description
What is your issue?
While working on #8778 I encountered some places where concat is used internally but the kwargs are not individually settable: stack and groupby.
#10062 hardcodes them to the old defaults: data_vars="all", coords="different", compat="equals", join="outer"
@dcherian mentioned (https://github.com/pydata/xarray/pull/10062/files#r1978040669) that we might want stricter behavior.