Not until today. Maybe exchanged with other events in combination?
Btw: This is the old thread 4.1, you should post to the sticky "most current thread" 4.2:
https://www.esoui.com/forums/showthread.php?t=8059
Available events are (taken from EsouiDocumentation_P20_2.txt of 4.2 update):
* EVENT_ACTION_SLOTS_ACTIVE_HOTBAR_UPDATED (*bool* _didActiveHotbarChange_, *bool* _shouldUpdateAbilityAssignments_, *[HotBarCategory|#HotBarCategory]* _activeHotbarCategory_)
* EVENT_ACTION_SLOTS_ALL_HOTBARS_UPDATED
* EVENT_ACTION_SLOT_STATE_UPDATED (*luaindex* _slotNum_)
Edit:
I've aded a hint to the ESOUI wiki at this event.