I understand what you're saying, but it all just depends on what the input/output bitrate was. I can see you possibly getting a legitimate 256kbps file at most based on the times, but based on how Mike says 'professional studio' in the .pdf files, that's probably not likely.
It's so easy for them to re-save a file as 320kbps.
I personally just don't see a possible way to plug a guitar into a mixer, have the sound go straight into editing software with a recording rate of 256 kbps max and then saving the raw file as 320kbps and calling it legitimate. You're right about the newer stuff though, no doubt. You might actually be right about all of this. I'm just telling you what I know from school and possibly saving you from spending your money on stuff that is labeled as '320kbps', but is not actually as it appears.