The part you quoted pretty much answers that. Don’t just half a** a zone and stuff it with WQs and a handful of dailes.
It wasn’t the same formula though. Suramar was made with that big quest chain as its center piece. Nazjatars story was just an intro questline that you could complete in about an hour or 2. Truth be told I can barely even remember the intro quest, whereas Suramars questline is very memorable. Nazjatar is an important piece of the lore, it deserved the same time and effort they put in to Suramar.