Doesn’t rising interest rates do a number on bond values?
They are talking about a short term bond fund. If you hold to maturity you get all your money plus interest. The ETF should be relatively stable if set up properly. However the ETF is a traded security. If everyone went to dump it at the same time you could theoretically see a loss in value.
Likely they are talking about retirement funds where your choices are limited as far as investment products available. Why wouldn't you just buy your own treasuries?