I doubt they are reconsidering you!! I bet they made a mistake when sending out the rejection email to you. But you could always email back whoever sent you the formal interview invite just in case. Also, do you mind DMing me with your PI? I never saw any posts about people getting interviews with my PI and am bummed because I really thought my application was a good fit
Has anyone heard from EB at the University of Illinois Chicago (UIC)? I saw some posts on GradCafe that people had gotten interview invites, but can't tell if they have all been sent out.