i believe that anet is trying to fix a problem they don't understand in the worst way possible here... a bunch of people complain online about the chonky hp bar of the boss, and the only reason they complain about it is because the fight itself and its mechanics are so tedious that making it longer with a huge hp bar only makes it worse.
the real problem is that the fight is FULL of mechanics that force you to stop chipping at the hp.
the worst offender is frightening speed (numbers mechanic)... first it forces you to spread out, then it forces you to watch as the boss takes their sweet time jumping from player to player to deal their unavoidable 50% of your health. and in cm after 33% you cant even range dps him cuz he fears you as well if you look at him. does this mechanic need to be such a huge speed bump on top of being a healing check? either let that slow hell be over quickly, or let us dodge the highly telegraphed attack, give us a reason to want to engage with the fight instead of forcing us to take a break every minute to watch 20 seconds of our time be wasted by this tomfoolery.
and that is on top of dread visage(eye mechanic) and the 66% and 33% phases also forcing us to disengage the boss.
the reason people complain about the huge hp bar is because the fight is a huge annoying chore and not an engaging encounter.... add to that the fact that it is full of punishing mistakes that can not be recovered from that would force the group to start it from scratch all over again and you get more than a few people willing to skip it than deal with it (specially since half of those mistakes are not caused by poor gameplay but rather by the sheer jank of it being an unpolished new release... personally i have been wiped more times by a faulty hook/mushroom or a delayed tether than i have by failing to turn around to an eye or spread to a number or bleed out from an axe).
you are trying to solve this problem by making this chore of a fight a bit shorter (but still just as miserable). you "fixed" the issues of the boss having too much health and the unavoidable damage being somehow avoidable when you should have been focused on fixing the issues that make people not want to engage with it.
don't try to make this punishment shorter in hopes people will bear with it, try to make it so it doesn't feel like a punishment in the first place.
here is my suggestion, make it so the boss only does frightening speed (numbers) if you fail to break his breakbar instead of summoning a new aspect that honestly people can just ignore along the other aspects they are already ignoring... the number of cc phases and it getting harder and harder would mean that it would be extremely hard to never see it at all, and players good enough to do it deserve that reward, and losing 50% of your health would be a suitable punishment for failing to cc in the first place, on top of making people willing to ignore the mechanic in favour of pumping damage regret their decision. if the group is dpsing fast enough that hey cant keep up the cc then the speedbump will serve its purpose as a speedbump.