To keep from breaking players saves however those with them get to keep them so long as they never sell or lose them after death. However in future we have an updated system for creating a more procedural variants for modules that will do the same thing as these hard coded weapons.
The new system should be way better and can apply to everything, not just weapons. So you might find a shield generator that generates a much more powerful shield than normal but say isn't as resistant to collisions or something.
Procedural variant weapons will be the random weapons, but applied to other modules too. We have a whole system of essentially "crafting" them from various resources and the like or finding them in wrecks but it's a lot of work and will take a while I suspect. It's more about earning special resources specifically for this system by doing various activities. Not just mine x resource and the use it to make a new weapon. It's more involved and deliberate.
I can speak clearly because we've designed it, but that's as far as it's gotten I'm afraid. I just wanted people to know that despite the variants being gone (for most people) that we were looking at a better way to handle them in future. I've deliberately not gone into too much detail about it because it's incredibly subject to change and/or won't even happen but I have the hope that it will see the light of day at some point. I just don't know when.