I think the security argument for carrying an alternative set of Posix-like utilities to Gnu Core Utilities is rather weak. These would mostly have been used to build other ports, or are you suggesting that this would harden the ports build systems (which already use privsep at that)? If so, I would take the lower maintenance burden any day and just wait for the Linux ecosystem to make up their mind as to whether Uutils becomes the new standard or not.