... because the new Developer Hub will have Flow enabled in all discussion pages, see phab:T103049.
Topic on Talk:Web APIs hub
The link at the top, http://devhub.wmflabs.org/wiki/API:Web_APIs_hub, is broken. Was https://www.mediawiki.org/wiki/API:Web_APIs_hub intended?
That was the old test-instance, using the blueprint skin, but it seems to have been deleted recently (per). I've updated the page to remove mentions of that side-experiment.