It was definitely risky (as most FA signings are) but Matz got the same AAV and an extra year. Just kind of the going price for a back of the rotation 2 WAR starter. The statcast data on his pitch movement and velocity as well as his projections all look good and it seems like Atkins has been on him for a while which makes me think he can unlock an extra gear from him.
You're right, GM's aren't infallible but it seems like Atkins earned the benefit of the doubt for me. Time will tell! Cheers