This article is misleading about SDRs. While you are correct that the value of one SDR is derived from a certain amount of money from several currencies, Special Drawing Rights are essentially pieces of paper from the IMF that allow countries to have an emergency overdraft.
These countries can then use these SDRs to convert them into any currency that they like (ie, Dollars, Euros, or Yen).
SDRs become a hot topic not because the financial system is having issues, but because governments don't have money to run. SDRs give countries that emergency boost of money to help fund their government.
While there are valid concerns that stocks are overvalued, SDRs will not be the solution. They're simply ways for countries to get money.