Both the topic summary itself, and the topic summary actions (in history) still appear, though the title is not disclosed:

(cur prev topic) 02:03, 15 April 2015 . . 10.0.2.2 (Talk) edited topic summary on This topic was suppressed by Admin . . (+3)‎ undo
(cur prev topic) 02:02, 15 April 2015 . . 10.0.2.2 (Talk) created topic summary on This topic was suppressed by Admin . . (+14)‎ undo

Maybe this isn't following root permission (since I think it's technically not a reply, direct or indirect, to the topic title). It might need a custom handler in FlowActions for view-topic-summary and history. Or root permission could possibly be changed to take it into account.