Steam Workshop submissions now need a moderator’s approval before they can go live. The change in policy was not formally announced; modders noticed it only on Friday in the Counter-Strike: Global Offensive subreddit.
A modder made a “submission test” to see what would happen, went to the page for the mod, and was greeted with the notice that the submission is awaiting approval from a moderator before it will become visible to other players.
Mod makers have been asking for some kind of mod moderation for a while, as the unregulated Workshop was becoming polluted with spam mods and scam makers, crowding out the work of legitimate makers (or in some cases, organizing botted downvotes of it so that their dreck would be most visible).
A new (undated) Steam Support Page explains that item approval is now the second of two steps for getting listed; previously, users would need only to verify that the submission was attached to a legitimate Steam account email address.
“For certain Workshops that have been the target of scams leading to hijacked accounts, newly submitted and updated items will be placed into a moderation queue,” the page explains. “The approval process should be completed in less than a day, with most items getting processed in less than an hour.”