Definitily dead. One of the speciality of Stratis team : Abandoning projects without saying so officially, leaving people out in the cold
Are you sure there is no way to get back our coins remaining there? By sending an email somewhere for example? It wouldn't be honest and professional from OP and TVE owners. I don't see any red or neutral feedback from DT members on his profile page, so he is maybe still offering an alternative solution.
https://bitcointalk.org/index.php?action=trust;u=289922100% dead.
That member don't works anymore for Stratis firm, since 2017 or 2018.