Hello Tim, welcome to the Wowza support forum.
By default Wowza is set to log the first 10 chunks or a live stream. I am pretty sure this has always been the case. There is however an option to log all chunks:
Setting the value to -1 will disable HTTP logging completely.
I could be that this company was logging all chunks in the past.
30 seconds is a long time, it probably means a 30 second key frame frequency.
The logs have changed in other ways since previous versions, usually just additional info.