web-ext sign --channel=listed --api-key=... --api-secret=...
This publishes and submits your extension for review
which sort of implies that
web-ext sign --channel=unlisted
should not submit it for review, which was always our experience and expectation until recently one of our test builds signed with
unlisted suddenly got reviewed. If that is indeed the new policy (which makes signing for test very inconvenient), perhaps the page above should be updated.