What is the meaning behind 3C3C1D119440927?

Solution 1:

The name is a combination of a few things. From the official Square Enix blog:

In case you were wondering what the name of the DLC means, we’ll give you a hint: 3 Costumes, 3 Colosseums, 1 Dream and Date 119440927. As for what this means exactly, we’ll leave that up to you to figure out!

This covers the 3C3C1D part, however the date is left a mystery. Fortunately, this mystery has been solved.

From this Steam thread:

"09/27/11944", which is a date from a collaboration music video called "Deserving of Life" by Amasarashi. The date is directly referenced in the beginning

Here is the music video for "Deserving of Life" by amazarashi.