Will the excess demand for risk-free assets disappear?

One of the causes of the low level of government bonds yields in OECD countries is the (ex ante) excess demand for risk-free assets (bonds). There should, therefore, be concern about the possible disappearance of this excess demand for risk-free bonds, due to: The increase in fiscal deficits in OECD countries, but the global private savings rate is also at a high level; The decline in the foreign exchange reserves of central banks , which are major investors in risk-free bonds; The end of the accumulation of bonds by central banks in OECD countries.