There are now 2 versions of Inspire 1 (v1 and v2) and 2 versions of the original XT (also v1 and v2). Both Inspire 1 models will accept either one of the original XT cameras. If you need your original XT to work on a Matrice 200 or 210, you need a gimbal adapter and a v2 XT. The v1 XT can be upgraded to a v2 XT by sending it in to have some electronics changed.
The XT2 however is not compatible with the Inspire 1 line at all.