It's sort of distasteful unless done really well.
2pac's lifestyle and the way he's been portrayed postmortem, it fits him and you know that it was more a tribute by his fellow artists rather than a cashgrab.
For some stars, I could see this being a tribute... Owen Hart I think is a bad choice, the circumstances around his death make me think they should never celebrate his death, but rather his life and showing us a 'ghost' of Owen does nothing but remind many of us of that night when the camera focuses on JR as he tells us that Owen had died. Someone like Eddie is different just because he lived his life a little more on edge, so I could see something like this, it wouldn't be a far cry from having him as a legend in WWE games.
The Holograms for Taker, I agree fit his style and aren't far from things we've seen him pull off, but again, the cost isn't worth it, it either would be expensive or look incredibly cheesy, and unfortunately, his career doesn't have long enough left or the exposure needed to make it a gimmick worth the cost.