Wow never new about thunderbolt 2. There is no end to it is there. Thunderbolt is so recent and now 2 is coming I read. By the time I buy a new mini 3 will be out. And my 2011 mini is already feeling so outdated. It will be 1terry-bit per second by the time I'm 65+ probably.
Anyhow as for the question should be backwards compatible unless they have a new plug or shape for the port.