the manga still going doesn't have anything to do with the ones making the anime.
The probability of the 3rd season is slim, due to it's not successful sales of the DVDs/BDs.
showing the "girls" now is a sign that have no plans on the 3rd season.Showing them means, "hey, we couldn't fit them into the anime, so we're giving they're animated version now since we don't plan to make a 3rd season.
Once again Bakuman taught me how the manga-to-anime industry works.