Explicit language might modify what would otherwise be there only by an implicit doctrine.
In general, a licensor can modify their own terms. So, if you are using the GPL on software to which you hold the copyright, and you add some sort of exception, it applies. You can't do it to other people's software.
I am still having a little trouble with "we don't need our spies to spy". Maybe we do.
I am also having trouble believing that the kind of encryption we use on the Internet actually stops the U.S. Government from finding out whatever it wishes although IETF and sysadmins might be kidding themselves that it can. Government can get to the end systems. They can subborn your staff. Etc.
MS language is potentially worse than the default. And there is room for litigation to surprise us.
Yes. The last stuff I wrote that I couldn't compile today was in "Promal" or "Paradox". My C and C++ code from 1980 still builds and runs.
All of my web development is on Ruby on Rails. That environment has had a lot of development and I've had to port to new versions. So old code for RoR would not quite run out of the box, but it's close.
Popular computing languages do not in general have only one Open Source implementation, and do not get abandoned.
If all else fails, lower your standards.