You're kidding right?
I said (before Cataclysm) that peoples' holdings prior to the rp could be different at the end of the rp and that, yes, you might be absent some planets and that some absences would not be explained. They just would be.
Of course, when you were presented with this, you were like "hey, my planet (asteriods) is gone!".
I could have just pointed to my comments above prior to Cataclysm but I went ahead and included a "story" behind it being missing (which was a pain by the way) and Vahaba become invaded.
Now you are missing another planet?
Are there any more factions missing a world or two or three?
Guess what?
The Dominion actually gained a few planets! I don't see Ahnk stating "Hey! I have too many planets after Cataclysm! That sucks! Change it back!"
The point is, yes, your personal planet list you saved prior to Cataclysm may be different than the planet list shown post-Cataclysm. Even if there is no story behind the world gone missing. Assume it had something to do with things..."Cataclysmy" and go on with life.
Of course, this complaint is a little different. The planet list was changing after Cataclysm. This was a known thing. And yet you still decided, in the middle of it, to swipe a planet from the LON in a separate rp and then incorporate your new world into Cata. Since the takeover was not a "part" of Cata, yes, it was lost in the shuffle from the pre-Cata planet list to the post-Cata planet list. Why are you being all shocked?
Put a notice up in the planet list thread with the link to the takeover so I can add it in six months. :p