how does this user hide messages in profile?

hey, i saw on hearthstone sub that https://old.reddit.com/r/hearthstone/comments/1t5d1d0/dear_hdt_devs_can_we_please_ask_for_a_feature/ok9fcom/ this user posts but those posted comments does not show in profile (profile is not locked), how is this possible? look at B_E's profile, this message i linked does not show in profile history. how is this possible?