Let's consider two threads A and B. Suppose a user posts a message M in thread A and no messages are posted in those two threads after that. In the list of threads A will be above B and in Updates column the timestamp of message M will be specified for thread A. Now a moderator moves message M from thread A into thread B. It turns out that this does not change the list of threads: A is still above B with M's timestamp and B's timestamp remains the same as it was before the message was moved. I would expect thread B replacing A in the list while A moving down according to the timestamp of the last message posted before M.