The two final bosses of the upcoming Nighthold raid will be up for focused testing next Tuesday.
Grand Magistrix Elisande was already tested over five months ago during the Legion beta (alpha):
On Tuesday, December 13, we will be conducting focused raid tests of Heroic Nighthold bosses.
Remember that Heroic difficulty scales for groups between 10 and 30 players, so feel free to assemble and bring a group of any size within that range.
Tuesday, December 13
Elisande – Heroic Nighthold
13:30 PST (16:30 EST, 22:30 CET)
Gul’dan – Heroic Nighthold
15:00 PST (18:00 EST, 24:00 CET)
As always, this testing schedule is very fluid and subject to the realities of a PTR environment. We might have to change the time of a testing session, change the bosses being tested, or cancel a test entirely, due to bugs, server hardware issues, etc. Keep an eye on this forum for the latest information, and thank you in advance for testing and providing feedback.
Q: How do I get into the raid zone?
A: In Dalaran, Orgrimmar, or Stormwind, you may speak to Nexus-Lord Donjon Rade Sr. in order to teleport into the raid zone while it is open for testing. (The option to teleport into a zone will not be available when the zone is not open for testing.)
Q: What character should I use to test the raid?
A: Whichever you prefer. We will be scaling players’ effective level to 110 for raid testing, and their item level to an appropriate threshold for the encounter(s) being tested.
Q: How long does testing last?
A: The primary purpose of testing is to give us the information we need to balance the encounters, evaluate how mechanics are playing out in practice, and identify bugs. Once we’re satisfied that we’ve received that information for a given boss, we’ll be shutting down testing. Usually this takes anywhere from 45 minutes to 2 hours, but there are no guarantees.
Source: WoW Forums