The requirement to maintain the required information has not been eliminated or replaced. A "log" has never been required - just that you have to maintain the appropriate information and be able to produce it on demand. Most banks found that a log was at one time the most efficient way to accomplish this. With today's more sophisticated deposit operations platforms, some banks have figured out how to automate the process.
So it is really up to you.
Just make sure that when the regulators show up and say I want see all purchases made with cash from $3-10K for the last year, you can produce it. Some banks that I have questioned - said sure, we can do that and then produced a list of every cashier's check sold in that dollar range whether cash was involved or not. I can tell you that is not good enough.