no its not necessary. its one of those things that vary from person to person, from alter to alter. some say it and some dont. saying "we" isnt a sign of acceptance of the disorder or the alters.

most if not all DID people that I know that have said "we" before diagnosis. for them it was a sign that there was some co consciousness (the host and alters know each other were there) an automatic response kind of thing.

After diagnosis people call their system of alters many things "we" "them" "they" "all of us" "the team" " the munchkins" as a designation when talking in therapy, a way to stop the confusion and way to avoid saying each of the alters names...

example when referring to one alter I would avoid saying their name and call them "she" or "we". I did not accept this alter and did not accept what that alter did. I did not approve of what that alter was doing, saying or what memories they held. and I did not accept the responsibility of what that alter did. the alter chose to go to bars, get drunk and what ever else she did. I did not have any part of making that alters plans activities.

for me saying "we apparently went to the bar last night" was like when a doctor or parent says " So how are we today" or "we do not do that, that is not acceptable" the doctor and parents dont literally mean they are included in the conversation. saying we was just a parenting or treatment technique.

which may also be why some people who have DID call their self we... because their parents always referred to their childs actions as "we are going to do this.." or " we dont do that..." they grew up hearing their self referred to as "we" so they do it out of habit.

theres all kinds of reasons why a person mentally disordered or not refers to their self as "we". for some its habit, for others its acceptance, for some its sarcasm, for some its wanting to be like other people that refer to their self as "we".... its all individualized... each person has their own reason for doing saying it or not.