That does not mean that the whole country is moving to Linux and LibreOffice, neither does it mean the government demands Microsoft and Oracle to give the source to their products. Existing solutions are purchased on licensing terms and they remain unaffected (although we strongly encourage the use of open source solutions for that as well).
It means that whatever custom software the government procures will be visible and accessible to everyone. After all, it’s paid by tax-payers money and they should both be able to see it and benefit from it.
I wish the United States would do something like this. This is fantastic.