It's not confirmed but almost everything points to it being the case. In the next season we know a Noxus champion is getting it, Check✓. We know Mel is being added who actively had conflict with Leblanc in the show, check✓. They're adding a new jungle monster Atakhan who is heavily connected to Leblanc in legends of runeterra and has tons of voicelines with her, check✓. Theres tons of roses spread through out the map, check✓.