Previously "they" (who ever they are) had a Federal Exemption similiar to what Excalibur Cobras had. In both cases when the exemption ran out, the doors were closed. I wonder who the new "they" are? Tracking Shelby companies is like going on a snipe hunt.
To get 'full blown' Federal approval you have to 'crash test' some cars and jump through some really tough hoops in general. Very tough.
My guess is this yet another exemption, cars might available for a limited time and at best in small numbers.