Recent and New

Recent is not new. Simple. Example: Yesterday is recent, but Today is new.

New sorts by the thread creation date, displaying the most recently created threads first.

Recent sorts by activity, displaying the most recently active threads first.

but isn't it redundant in the first place. isn't new threads just gonna overlap recent threads?

Nope. If somebody created a thread 2 months ago and is still active, you'll see it in the Recent view, but you won't see it in the New view.