The Basel Capital rules dominate at the moment. If that ever gets rolled back... buy gold immediately.
Oh ok. So there’s a difference between reserve requirements and capital requirements. Capital requirements are still in place Basel III (Basel Capital Rules) 4.5% among other requirements https://en.m.wikipedia.org/wiki/Basel_III
Basel III also specifies liquidity requirements, which basically means banks need to hold sufficient loan assets in the government or central bank (generally bonds or reserves respectively), which act as a backstop if other banks stop lending to them (i.e. stop accepting deposit transfers without also being given an equivalent asset).