using FED's SRF for liquidity means cash/liqudity is scarce
there is a lot of short-term debt to be refinanced or default
default is not an option. thus, expect liquidity injections from the central bank
repo funding rates are predictors within this global, multi-factor liquidity context
you can use them to understand liquidity flows in the near future
this is also because repo markets are short-term debt instruments - so the signal is also more short-term