I wanted tt_news records to be not hidden by default, but only for a specific user, who edits my "Small Talk" segments. The "Small Talk" section of my site consists of very brief news segments, kind of like Twitter "tweets", that wouldn't require any further editing once written.

So, to make sure that the "hide" checkbox wouldn't need to be unchecked for the user when new news records are created, I just edited that user's TSConfig so that the following was added:

 // Don't hide new news items

TCAdefaults.tt_news.hidden=0

Now, every new news item created by the user is automatically unhidden by default.