I noticed after unlocking the Moon Bunker last week, a notation near the bottom of the Terminal window that I cannot explicitly recall being there before in the past (or I have since forgotten).

frozenshield systems     ‎ port 31.7.39 sjs

This made me curious enough to run back to the EDZ Bunker and bust it to verify that the same wording was on that Terminal as well. It IS there.
So I went a step further and headed to Mars to check the old Mindlab: Rasputin Control Terminal from back when D2: Warmind was released. I seems that it is there as well, although, you cannot zoom in to read it clearly since weapons are disabled in the non-combat area.

While taking the pathway to get to the Rasputin Terminal, I feel like I was possibly noticing new safety markings on the floors, objects, doors, or possibly a new graphical pass/spit shine on certain objects? Certain things seem slightly a little different than last time I was there, long ago? Or am I starting to go stir crazy?

Does anyone recall any frozenshield mentions in the past?

I haven't been coming up with anything through text Searches. But I don't tend to be the best at Google-fu (I missed the Bungie.net article/lore post that revealed Saint-14 and Osiris as being Brothers, then I posted, wondering about it only a few weeks later when searches turned up nothing definitive.

Could the frozenshield mention have been used in part of that Warmind Puzzle that lead to the Valkyrie Spear Replica Geo-Cache that was found hidden in a Regional Park in Upstate New York (near Vicarious Visions)?