I sincerely believe there is no dev at Blizzard now who knows how the game originally worked. They have no idea at all how the classes were supposed to function.
All one need do to confirm this is to look at retail classes: homogenized, oversimplified, removing base abilities and giving them back as “talents” – They took those glorious class builds from MoP and turned it into what it is now, because they haven’t a clue how to manage the complexities of the original math/mechanics.
They are clueless and can only be guided by the notes left by the original dev team. Apparently, these are not complete and Blizzard’s present Classic team are at least giving it a try.
It might be helpful to them to make a separate thread specifically laying out how it is now and how it was then.
They mistakenly think this is not a bug. However, since it clearly did not work this way in Vanilla, it is a bug or a completely unwarranted change. It is possible this is some crapcode from Legion… shrugs
But lay off the caps and the rage. It’s frustrating but they won’t even hear you if you rant.