BuddyPress.org

BP 1.2.7 might address this problem.

In the meantime, a temporary solution to remove the identicon is posted here:
https://buddypress.org/community/groups/how-to-and-troubleshooting/forum/topic/am-i-going-mad-or-are-there-now-avatars-next-to-posts-in-the-activity-stream/?topic_page=2&num=15#post-76621