I expect that this is a NiM Denova mechanic that has leaked into HM. they possibly tested it to see how it would work and forgot to take it out when they released the patch.
I wouldn't be too upset by this, atleast it gives you a little bit of practice for the start of the nightmare mode fight :P
Same. To be honest, not only did it actually get us a bit more awake (we're a PST/EST guild so while it was 9 pm for me it was 12 am for the Raid Leader) it was nice to have a new mechanics to adapt to.
Still, I realize I was a bit selfish when I request that they leave this in, it's not fair to people who haven't done HM EC yet (it's just that I'd forgotten anyone hadn't).