Dude shut the fuck up with the nonsense of bad luck protection for legendaries.The raiding scene on my server seems as active as ever.
If your raiders quit over new progression on professions (not a reset), it was probably long in the making.
And time spent in-game grows by the quarter, so "what you can do about it" is either recruit more, or join a guild that isn't falling apart. This held true for every iteration of the game, FYI.
AP catchup is extremely potent, "new players" not "having AP" is bullshit. Concordance is easy to reach, and going beyond that is made easier with every week as new AK is added automatically.
New players not having Legendaries is not a problem, they'll get them by playing the game through bad-luck protection. Will they have a pile of leggos to choose from off the bat like players having stuck with Legion since the start? Probably not, but that's the price of playing an MMORPG where someone's always going to be more progressed. "They have to play a lot" sounds pretty funny, considering they willingly signed up for an MMORPG in the first place, not a single-player game... If they got the drive to raid, they got the drive to progress their characters to an acceptable level.