Unified view enables recording much more information for the guest then does database view. Some of these fields are: Participation level, Invitation status, Invitation date, RSVP status, RSVP date. As all these fields are new to guest, but a must for working with Guest in Unified View Events, please add these fields to Import so that we can Import the data when we Import the guest.
All these fields are available in Database View. Are you looking at the participation record for the guest or the "add new guest" window from the Host's participation record?