When plotting to overthrow the Byzantine empire, if you are in seclusion because of disease etc, when you take the empire, you are locked in seclusion with no available decision to exit seclusion.
tested as the duke of Sicily in the 769 start.
Would also suggest that same religion group be allowed to use the: "claim the empire decision", seeing at least in the early bookmarks there was a historical struggle between the iconoclasts and the orthodox church.