EDIT : It appears the change listed in the patch notes hasn’t actually gone through yet. Please don’t fix the bug, it makes the game more interesting.
Having full health bosses spawn in, especially during events, was quite literally the only way to get some form of content in the game that had a chance to challenge a 4 man group. Monstrous Specialists used to be the single best condition in the game, due to being the only chaotic one, the only one that added anything during events, and the only one that added something meaningful to the game.
Barring thunder hammer cheesing, it created tense scenarios that often required utilizing the map and splitting the team and boss aggro to complete objectives.
Weakened bosses are too weak. They get nuked even by things that aren’t normally geared for boss damage and don’t pose a threat at all, mostly serving as a very brief distraction. If you are going to be removing one type of monstrosity, I suggest removing the weakened one. If you think this makes the game too difficult, simply land in the middle and give us bosses with 50%-70% max health…
Or ideally you could simply revert this change and give us back the only modifier that was even remotely fun to play at a high level.