Board Thread:Sonic News and Updates/@comment-29621263-20160814061718/@comment-1031724-20161019223809

I've addressed this before.

His appearance in White Space is non-canon, as are any of Sonic's revisiting the levels a second time (well, technically a third since each is a level from a previous game), it's just a way to let the player do them again, like all the levels in Bomberman. Anything Sirius changed after he was revealed to be evil, yet Bomberman couldn't have revisited them in canon.

Second, he could have used his liquid metal shapeshifting powers to revert to his Classic self for the occasion, and even if it was his past self, his death would likely have been merged with the current timeline, not erasing any games he was a part of, but causing him to disappear in the present.

Third, it isn't the same fight in Sonic CD because it's the Bad Future of Stardust Speedway, one that would have been erased from history much like Crisis City, and Metal Sonic physically took Sonic to that point in the timeline.

Fourth, the actual fight in Sonic CD didn't have him kicked into the air and explode, he crashed into a wall and fell, but his body was intact allowing Eggman to revive him.

And thus I've inadvertently opened another status debate about Metal Sonic, we do this every single time!