Why is there a staggered release only for the first tier of Savage and the Ultimates?

[Vnolan]

So people have time to experience the MSQ at their own pace without feeling rushed to get to the end. It also gives people time to gear. The second and third tier come out so late, you have plenty of time to get gear from the previous tier as well as finish MSQ.

The devs want people to be able to take their time getting through the main story at launch, rather than feeling like they have to rush it to get straight to the endgame. This isn't considered as much of an issue in later patches, since people have had months to catch up.

Then why are the Ultimates released at a later date? You can't say 5.2 is when they decide everyone has had enough time to catch up because the 5.3 Ultimate will be released a few weeks later.