I'm a developer myself (.NET, Java, C/C++) and I believe those changes in the code indicate that the team is removing so called "debugging" outputs. When you are in the process of developing and want to track specific processes in the code to verify they work properly, you add those lines that show you additional information about each step of the process you're working on. Once you're done with that part of code and you don't need to verify it any more, you remove those debug lines because they're no longer important to you once you know the code works as it's supposed to