I'm all for having a condensed path through significant parts of the expansion story of
BfA (and other expansions via Chromie Time) and a good concept for that would be
Taliesin's "Path of the Curator" idea.
If it's just the
recommended, but not mandatory path.
Any player, even a complete newbie, should be able to access the current expansion's content once they reach level 48 (then 58) no matter how they reached that level. Maybe they cleared all the side quests, ran dungeons over and over, doesn't matter.
Once they can, they should be allowed to "skip" (read: leave behind for later) older content to jump into current content.
Forcing players into the story would be copying FFXIV's biggest flaw, one which players starting in the past year overlook because they wanted "something not WoW" and because "reaction streaming" is somehow so popular. Having several expansions of story to play through of course also delays the realization that even there, the maxlevel content will be kinda repetitive after a while.
Skipping older iterations and only reading recaps is something that's the recommend consensus for e.g. the Witcher games, which also have a strong story focus.
And WoW was always built on playing the current content with other players, not trawling alone through the entire story.
By all means, give players also the opportunity to enable a mode that keeps you at-level for content you outlevel, so you can play that without oneshotting everything, but forcing people through every step of a story is the wrong approach.