the tournament scene saw the tomb Kings nerfed long ago with "test points" that became their actual points. Then they got nerfed again when their resurrection spells and synergies were removed.
That wasn't "long ago", the compendium update and new points only happened this past summer. The tomb kings points updates were previewed before that, but not all tournaments used them, and even in those that did Ruler of the Night and red fury still anchored viable lists, and even the tomb kings points hikes weren't unreasonable bad until they were compounded by rules nerfs in the compendium update.
Again, it feels like a the distant memories of a lost age, especially with the quickfire release schedule, but in terms of actual rules development it was practically yesterday. If, instead of Malign Portents now, we had seen a mini campaign set in Ulgu to introduce Morathi, with the Shyish campaign and Legions of Nagash delayed six months to make room, then I think the rules in Legions of Nagash would be much different, a reaction to our post-GH17 mechanical doldrums. But as it is, this book was probably written before those doldrums even started, and is still a hot-touch reflex reaction to our previous strengths.