Felipe Contreras [off-list ref] writes:
It doesn't make sense to push to the upstream branch, so create new
configurations for the notion of 'downstream' branch, which is basically
the branch to push to by default.
It doesn't? That depends.
To people coming from (and people who are still using) central
shared repository workflow, pushing to anywhere other than the
upstream makes no sense.
If qualified with something like "When using a triangular workflow
to pull from one place and push to another place" in front, I can
see why having a separate upstream and downstream makes sense, and...
The upstream branch is remote+merge, the downstream branch is
pushremote+push.
... this is a perfect explanation of what a downsream is.