I doubt the 30 second extra on the enrage timer will suddenly make everyone kill the Dread Guard. So far all the kills I've seen have had Kelsara enrage and not die until well into the enrage. Guilds who are not ~top 25 (worldwide) will spend a lot of time wiping on the mechanics and only then have to worry about enrage timer, which is still extremely tight.
We barely hit enrage by 1 second and ONLY because our top DPS died 20 seconds prior. And you can't cite group composition either, because we definatly didn't use the prototypical setup (aside from using 3 ranged/1 melee)
That kill was 1 shadow dps, 2 commando dps, and 1 gunslinger.
So lesson of the story....surround yourselves with talented players and ya'll can play whatever the heck you want and compete at the top level. IMO I'm confident that, a critical examination of my group members, that at least 6 of the 8 individuals listed in that video could play any class in the game at their max level.