Louisiana has outdone the communists of decades ago. Under communism in eastern Europe black marketeering was prolific but not subject to such draconian measures, to the best of my knowlwge.
I am not an american so no direct knowlege of their laws but it seems to me that such a law is itself illegal because federal laws regarding legal tender should have priority.
It just shows you what a government can or could do to you if they wanted regarding your assets or investing.
Hence the holding of your investments personally is likely to be a necessity.