Several Web Services return basic user information (id, fullname and the profile image url) this should be enough for displaying a participant/contact information even when the WS available cannot retrieve the complete profile information.

This is especially important in the Messages contacts view, there we have the user basic information but the contact page cannot be displayed because in some cases the current WS is not capable of obtain that information. If we cannot see the contact page, we cannot do basic actions like add the user as contact or block/unblock the user.

Note that this is working in MM1 so it should be available in MM2