On the PBE right now the collection tab has been changed so that the main focus of it seems to be to sell you Eternal's. Many of the annoying changes include;
The small face portraits are replaced by the full splash, cluttering the screen.
The Mastery banner has been shunted to the lower right side in favor of an Eternal progress bar.
When clicking on a champion, the progression tab is there first, even before the overview and abilities, which seems like a cheap marketing tactic.
When you own a lot of champions the list goes on forever taking up extra time.
This tab really needs to be retooled or reverted because right now a lot of the functionality and design space has been lost in favor product advertisement.
(Idk how to post a screenshot on the boards so I will link my Reddit post with the image).