Have not seen a screeny yet, but I noticed that as well. I was making a big push to hit t5 as quickly as possible, but this forced slow down has really made me lose interest in the game. Hopefully someone will post a ss soon.
The Mk X "prosthetic" weapons have been in the game for a while (they're crafted using samples dropped in the Defera invasion missions). So this is just the way they're introducing higher mark versions to the game.