Well ok, what shuold be in Legion account wide to make all less alt unfriendly? Only 2 things (and again you only read the first part of post it seems): 1) Artifact Power / Artifact Knowledge and 2) Reputation; And here we cuold argue how it shuold be done and so on.
As boring as it cuold be, you can't make account wide the class order experience, it wuold make 0 sense. In WoD it cuold have been a thing, because Garrison was not tied to a class story.