The upcoming Nobility Quests will feature several quests that involve something occurring around one of your fiefs that requires your attention. One way in which you'll be notified of this comes in the form of the castle messenger who'll join your party if you are nearby your own lands to let you know what is going on. You'll be able to send him packing without consequence for most quests or let him know you'll ride back towards your estates soon enough which will spawn the Summoned to Your Keep quest.
The reason this is important is that this is what I will later refer to as a gating quest used to setup information for later quests. This simply gives me more ways to track what is going on and redirect you towards an appropriate sub-quest. Expect to be needed back at your home from time to time when 2.6 comes out. Now as to what the keep needs I'll wait for the next update.