The FAQ page looked interesting, but was full of questions that nobody asks. The only one that is truly a frequented inquiry is, "Where is the 1911 R1 made?", but they don't exactly answer that with definitive specificity, they just say where it is 'built'.
The word MIM does not show up on their site whatsoever. I typed 'MIM' into their search box and it caused a catastrophic error. I then conducted an Advanced Search from Google of that 1911r1.com domain for the term 'MIM', 'metal injection molding/molded', and turned up nothing, zip. I think that confirms and answers that question.
I'm know they are well aware of the MIM issues/controversy, and for them to specifically omit that subject speaks volumes. But we'll see.