Context on the Ornn PBE Changes?

So Ornn’s W is getting changed on PBE:

> Bellows Breath (W) initial fire damage change from [15/17.5/20/22.5/25% of enemy's current health] to [10/11.5/13/14.5/16% of enemy's max health]

Is there context for this? From what I can tell from experience and r/ornnmains, his damage may be lower, but it doesn’t feel terrible. It helps him not feel oppressive compared to the damage of the more recent tanks as his damage will get less over time. So why does he necessarily need to deal a % of the target’s max HP on an ability that’s AoE and has a lower CD, especially so soon after his mana buffs? What’s wrong with the %current HP damage?