The Seer nerf update makes some sense, but it misses the point: the really broken aspect of his kit is the interrupt from his tactical. Seer's Q cheapens other player's strategic actions, without exposing seer to additional risk. Even with a longer warning period, he's still most effective against the weak/injured who can't afford to move from cover. That's not art, it's abuse. Seer actively encourages players into the churn of attrition by adding additional risk to the difficult prospect of hiding long enough to stay in the game.
There is no elegance. His abilities lessen the flow state of play in a very one-sided way, and the frequency of his scanning still breaks the fundamental information balance like "silent movement" audio bugs do for Octane and others. There is no degree of skill that reasonably counters the prospect of a silent, invisible adversary who knows where you are.
If it were faster to cancel a healing action (or any action), or healing didn't slow as much, Seer's Q would be reasonable. If you knew you were being heart-scanned and could hide from the scanner in some way, Seer's passive would be ok. This is not the case. Seer still effectively possesses both a first-shot and last-shot advantage.
While the nerf is appreciated, I have to mostly agree that it makes him less fun to play while keeping the game-breaking elements in place. I respect that it might be too difficult to remove the interrupt mid-season. Either way, time will tell if the nerf is enough to reduce the constant dread Seer adds to the game.