The two articles quoted are not entirely correct. While the first article written about 4 days ago was merely a speculation while the other on Coindesk was since December 2017 which was expected to happen considering that was the time when everybody wanted to invest in bitcoin due to the All Time High witnessed at the time. If the news is anything to go by, I expect that they should have finish their planning for six months and invest as planned but of course its not happening. Anyone who invest based on "planning" does so at his own entire risk.
The whole thing is pure speculation.
Countries can't invest in something like the average Joe
Who will buy those coins, the central banks are the only ones that can purchase debts or make investments in bonds or gold, the government can't just allocate funds from the budget for buying cryptos.
And to do that they would have to deal with legislation, send the laws to the parliament or congress or whatever depending on which G7 country where talking. If any kind of move like that would be even planned we would have heard about it already.
Pure and old and outdated speculation....unfortunately.