Please note: the source code of Windows 10 can be requested if you are a large enterprise or a government already (as long as you agree that you won't release it). The only possible significant difference here is the lag - you can read the source code of the internal builds, whereas you can only access the corresponding source code for stable builds officially. So, if you are a government, you can actually request it for a legitimate purpose and pass it into the other side of that government if you really want to.