Idk why. It's not like many of these things or even the things on there are difficult to really get.
because if they make everything available they won't have new stuff to swap in next time if it turns out to be a popular event?
I assume the point of this is to entice new players to try collecting the others and get them interested in doing different content outside of MSQ. For old players it's totally pointless. We either have them, or farming them would take way less time than collecting the tomes.
I think the only thing I want from that is one of the void ark set minions, and only because my luck on them has been horrific.
Wouldnt have minded some of the Aquapolis orchestrion rolls (because thats still a headache and a half), or Rise of the white raven, as my only copy of that one went into Answers, and I feel a little silly now.
I imagine this won't be the last time we see an event like this and that they're going to cycle the "obvious" items in for the next rounds.