Thanks for the summary.
If you are dying to use cmdliner.2.0.0 then don’t die for that but you can always use the repo version for those package that support it. I have been living with opam pin add ocp-indent.dev --dev for a couple of months now. ocp-indent has seen a bit of activity by @NathanReb recently so I’m hopeful we’ll get a release soon.
For alcotest I see a release is on the way (thanks @dinosaure) but technically alcotest can be unblocked without a release: one can also PR the opam-repository to modify the opam file not to run-test: (that’s the case for a few other packages). See this discussion.