Yes, it’s the same as mitm. I get that it’s to avoid gendering the term but it doesn’t really roll off the tongue or preserve the existing abbreviation. I’ve heard the alternatives: machine in the middle, mallory in the middle or, my favourite, Malcolm in the middle.

I hope this becomes the norm. Having tried to form a bargaining unit myself I can tell you it’s an uphill battle. Some workers are vehemently against it still and they will successfully encourage others to act against their own class interests.