Has the problem with WHM in raids fixed in SB?

[Ghishlain]

Not true. At level 68 you get a trait that if you crit with Benefic I or II, you have a 100% chance to decrease Lightspeed CD by 5 seconds. (Wow WHM has a similar one right? except it's a 20% chance after crit'ing...) All these CD's are on a 2 minute CD except Lightspeed which is 150 seconds.
And anyways, if you want to talk about things not lining up properly, the same exact goes for WHM. I've mained WHM throughout the whole expansion and done almost hundred clears on the EX primals with it, and I can say it's extremely rare for everything to line up.

For WHM, the two major CDs you'd like to combo together on the WHM kit would be Thin Air and Presence of Mind and in some cases it's more beneficial to use them separately depending on the fight - so it's not necessary to have your CDs line up for optimized usage. I could see the argument to put Swiftcast into Thin Air to get a 5th GCD without any server issues but otherwise most WHM CDs can operate independently without hampering their effectiveness.

I will admit I forgot about the Hyper Lightspeed trait so comboing Lucid Dreams + Lightspeed + Celestial Opposition is certainly much more plausible. I still stand by the statement though if you had a choice of tools to use for MP efficiency, you should focus more on Lucid Dreams than Lightspeed. Though not everything in the AST kit runs off two minutes. Collective Unconsciousness, Synastry, and Largesse all are 90s CDs and holding onto them to combo with Celestial Opposition will lead to overall less uptime on the buffs / HoTs provided.