You wave goodbye to the Dersite Agents and wish them well on their travels. If it wasn't already clear from their questions, you've seen for yourself that the Dreamers are entering the Medium. For better or for worse, everything is going to change soon. Just because Skaia is gone doesn't mean its prophecies have been voided.
The Light Keeper has penpals on Prospit, so you were able to relate to the Agents how Skaia's disappearance created mass panic; the increased shipments of comestibles from Derse (and, you hear, the inner planets) attest to the disastrous effect on Prospitian agriculture, not to mention the loss of the Ecliptic Prophecies and the strange effects of new atmospheres on the residents of the moon. Even more alarming, in some people's view, was the fact that one of Prospit's Dreamers disappeared along with it.
You personally don't have anything against the Dreamers, and although their adversaries' power comes from the highest authority, you can't help hoping they don't get hurt. A lot of Dersites feel the same way, or they wouldn't put so much effort into hiding them.