Even if we ignore the mess that is TBC and WOTLK between Cataclysm 1-60 and Cataclysm 80-85 still is very hard to play lore in chronological order.
Let’s say I want to do all the content from one expansion like Cataclysm content from 80-85. If you are level 85 you have available all the leveling quest from Cataclysm that you have not completed and every quest chain that was available at level 85 are available too, that means is everything mixed, level 85 content from launch, first patch, second, etc. with no indication of where is the order.
And the same happens with MOP, Pandaria, Legion, and BFA. You reach the max level and all the content is available at the same time with any indication of what is the order. Quests, dungeons, raids, all available, good luck finding the order. And then we have the questlines that were important for the story that was removed like Pandaria and WOD legendaries questlines.
WOW requires to have a Main Quest Scenario like FFXIV that guide the player thought the story in chronological order. Not necessary to be mandatory like in FFXIV, but at least allow those who want it to play in order. So for example if I want to play BFA content in order 8.2 quests will be hidden until finish quests from 8.1.5, and so on. And the same for old expansions. Is not so hard, they only need to link the first quest of a patch with the last quest of the previous patch and only for players playing the story like a Main Quest Scenario.
They should expand Party Sync feature, that has the important thing of allowing to replay quests, and add in the Adventure Guide a list of quest lines, zones, dungeons, etc in chronological order allowing those who want to do it to play in order and enjoy the lore. Including of course removed quest lines, they could add those only to be played with Party Sync mode, that means there are no rewards, so old players will have still the exclusivity of their achievements, mounts, legendaries, etc and new players can play all the lore.