I understand the new operation is coming next month, i also understand you can't have a solid release date, you certainly are polishing the last detail right now.
I do think 4 bosses is too short, ideally you'd have around 8-10 boss. The tier one (EV and KP) did have that.
EV and KP had 4 each, so unless thats what your saying and ive misunderstood you, your wrong.
While i do think 8 bosses would be cool, i for one know that i could not do 8-10 bosses in one night, and having to clear 2 nights a week for a raid...