here is my personnal experience of the new instance if it can help anyone, so i heard 1 shotting first boss with scout snipe bugs the door and you cant snipe without agroing the boss first. trying to 1 shot without agroing first with ch/m rampage might be a way to get further into ez mode.
as far as trying the boss itself, it seems like it goes into the banka after taking 10% or it's hp in damage, if you bring it below 80% before it happens it bugs and you need to reset the hole instance. as said previously, some orbs spawn and follow some ppl, need to run it into the boss to make it reapear. having a melee wd pet hitting the boss will make him respawn imediatly when the boss reapears, he will teleport someone to him and deal about 80% damage to him.
For the rest i'm not as sure, i know ppl need to move to avoid shifting sands which seems to be like an invisible version of kbn 6th bombs that you also have no idea when it pops, there are also debuffs that reduce casting speed and attack speed by a fair margin, doesnt seem to be cleansable. on top of it there seem to be aoe dots everywhere, basically bring a druid if you want a chance to do anything, since you want to be moving, and even then might just get pulled it and 1 shot coz right after taking 80% of your hp not only are you stun but the banka which is untargettable might just run after you and white hit you for a bunch.
basically what needs to be figured out is how to avoid shifting sand consistently and how to either avoid having someone pulled in or how to make sure that person doesnt die. hope it helps
sidenote: having invisible trash that can 1 shot coe hm rdy tank on ez mode seems a bit ridiculous and not fun to me. same for boss, getting crowd control + heavily damaged by some invisible aoe feels pretty bad.