Warlord's Bloodlust "hotfix" changes nothing for Yas/Trynd; let's halve the heal for melees instead.
There are many effects (like Frozen Mallet's slow passive) that are only half as effective if you are ranged rather than melee. This would be a perfect opportunity to reverse the precedent.
The Bloodlust heal is designed to benefit ranged ADCs. Changing it so it only procs on champs and with a 2sec CD is fine on paper, except extended dueling is exactly what Trynd and Yasuo want to do anyway. Trynd will still proc the heal at least twice; once during the actual trade, then again once he catches up after slowing the enemy with his W chicken shout. Yasuo will proc the heal every 2 seconds regardless of how long a duel runs because he'll have 100% crit chance at two items, so this just rewards Yasuo and Trynd for getting in the faces of their opponents rather than thinking about trading intelligently.
Instead, if we halve the heal for melee champs, we let the squishy ADCs who were meant to have crit-sustain have it to the fullest (15% of the critical hit); meanwhile, the melee fighters who are more than likely building tanky or sustain anyway don't get to abuse it since they only heal for 7-8% of the hit.