|WARNING: SPOILERS AHEAD|
This article contains spoilers. Proceed at your own risk.
Tres Alicias is a reference to a possible sequel or a tie-in to another game not necessarily a sequel to VA-11 Hall-A, like how Read Only Memories is a game set in the same universe and with a ton of references, despite them being completely unrelated games. It might do something with N1RV Ann-A, the next Sukeban game.
After finishing the Anna Extra Night's Demo, you unlock 'START': a mini-story that takes place straight after the end of the main game. In it Jill and Anna have a conversation about various topics based on which dialogue options you chose. After selecting every option possible you are treated to a mini-logue at the end; Anna (who is listed as the speaker in the dialogue file) talks about trust and truth what they are over a picture of herself in crutches (dubbed annacrutch_cg_obj in the same dialogue file) before the screen fades to black with See you at Tres Alicias... appearing in the left hand corner.
Hidden Files Edit
VA-11 Hall-A Edit
Some images were found in the game files of VA-11 Hall-A. They were mentioned by developers in note for Patch 22.214.171.124. Developers are pretending like there's no such thing.One of images contains list of letters which can be deciphered through a reverse-additive cipher; they translate to "HEARDINTHEECHO", which is the name of a file in the app data folder for VA-11 HALL-A. This file, in turn, contains more letters that translate into the following (with slight modifications as a result of possible errors):