Many of the boss fights in existing content require players to dodge attacks less we want to run this risk of dying. That is fine.
What is isn't fine is having watch the chat/battle box for these attacks as it distracts us from the myriad of other happenings that we've got to keep track of such as: buff timers, player HP, ability cool downs and positioning.
I believe adding in some boss grunts would free up head space and let players play a bit more efficiently instead of feverishly glancing at a small box of text so they can react to the boss' attacks.
The most recent, and probably best example, would be the Nael Van Darnus boss fight.
He has a multitude of abilities which can destroy a player who isn't keeping tabs on their chat box quite easily.
I don't think the player base would have too much quarrel with only having in battle boss dialogue spoken, as at some of them have the brains to know that having every line of text spoken is a massive money sink that could be better spent elsewhere. But at least having someone orgasm "ahhh..." into a microphone would be a great help for the players who are having trouble knowing when they should be running the hell away.
A simple addition such as that would have greatly improved that boss battle, and if it is implemented into future boss battles in 2.0 a great deal of strife would be spared.
Also, inb4 a colossal clump of stupidity stumbles into the thread and says "It isn't a problem if you just play better.", and while that is true, it just isn't fun watching a box of text while I'm getting graphically pounded by Darnus.