At this point in time, totally unimportant. It's basically the vestiges of a system that was a nice idea when first proposed, until it hit the reality of the real world.
The packstate system was a way to allow pack creators to re-tag their files, and then distribute a simple text file that tracked the renames and automatically implemented the renames without the player needing to re-download the entire pack. As I said, it was a nice idea. I created initial packstate files for my packs for a while.
The reality that hit was:
1) Pack makers rarely update their packs, at least not just my re-tagging the files. I almost never edit my old packs anyway. Other makers do, but it's generally to add new files, which defeats the purpose of the packstate.
2) For the packstate system to be effective it needed some way to distribute the packstate files. While the system was fully implemented in the game itself, there was never developed a system for distribution of the packstate files. Without that, the system never received the input it needed to update the pack file names. I eventually realized that noone was using the system and stopped generating packstate files, and eventually removed those that I had from my Mega.