So in an interview Pristin said that Pledis entertainment chose which track off the album would be the title track and I think I have a theory why they picked Wee Woo.

Pristin put out 4 cover songs before their debut.

Catch me if you Can

Rum Pum Pum Pum

Very Very Very

and Adore U

I think Pledis uses these covers as a testing ground for new concepts. Pristin said in another interview that they experimented with a lot of concepts in their predebut covers.

I think each of these corresponded to a song off the album. Catch Me if You Can was similar in concept to Black Widow. Adore U was similar to the Power Pretty concept of Wee Woo. Very Very Very was Running and Rum Pum Pum Pum was Be the Star (all concept wise not in how the songs sounded exactly)

Now the most viewed Cover was Adore U and the 2nd most viewed was Catch Me if you Can. (But I doubt they look at YouTube views so that's not the point) I think Pledis picked Wee Woo as the title track because Adore U was the most popular cover they did and since since Catch Me if You Can was the 2nd most popular they decided to promote Black Widow on the side.

It just a theory but I think it makes sense, especially because in the same interview they said they want to keep the Power Pretty concept because they think it's unique to them meaning Pledis still thinks it's the most popular concept they can show. Any thoughts?

Edit: Links to interview translations