This seems to have gone under the radar for a long time now but back at the beginning of season 9 the PIEC (Player Immersion and Expression Content) Team released a video called "Skins in Season 2019".
At minute 2:52 Riot IAmCarlos says:
Outside of skins, we've been working on a new product that will be introducing a new way for you to track and showcase your skills and your accomplishments on your favorite champions while you flex on your opponents in-game. Keep an eye out for more details on that product in the first half of the year.
We're already on the last month of the first half of 2019 so we should be getting more details on this new product really soon. I've been hyped about this for the last 6 months but I can't even think of a single thing that this teaser may be hinting at.
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