But only for first-party titles from Valve.
Steam Workshop TF2

You may have already seen that news going around that items on the Steam Workshop must now be approved by Valve before they will appear for the public. This seems to include anything that you may typically find on the Steam Workshop, including custom maps, models, skins, sounds, and the like. This first showed up via a Reddit post on the Global Offensive subreddit.

However, this approval process is not for every Workshop enabled game available on Steam. At least, not yet.

Right now, this approval process is only be implemented for Valve's own titles. Specifically, Steam staff will need to approve Workshop content for Counter-Strike: Global Offensive, Dota 2, and Team Fortress 2. These new rules are in place in order to combat spam and scammers that promise things like "free skins" or other freebies if they subscribe to their Workshop content.

Valve does say that this is not a blanket moderation queue. Those content creators with a large number of voters or subscribers will typically not have to deal with the moderation queue. Plus, Workshop items for other games are currently unaffected. However, they did leave the door open for this system to be applied to other games where similar scams are prevealant.

According to the Steam Support page for Workshop content submissions, the verifications and approvals are now a two-step process for these games. The first step is an email verification. The second step is the moderation queue.

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. You'll be able view and edit the content during this process, but other players will not be able to view changes until they're approved.

For updates to existing items, subscribers will have access to the previously approved version if there is one.