Here's my experience.... a few days ago I noticed something too. Publications appear at the top of my feed, along with people I follow. When I click on one, as you say, it goes to the latest, which means lots of scrolling, because the stories are not three abreast anymore. That's annoying on a laptop but might work better for users with phones. However, I also noticed, that if I went into the same URL on a new tab, it reverted to the original layout, three abreast. I've done just that with AP, and your original layout is still there (three abreast). So it might depend on how you access it, as to what you see. And it's happening to ALL publications.