Notice how none of the other clips have actual sound, and how Master Xehanort's words don't match his lips....
If this were an actual trailer, there would at least be a few battle noises accompanying these two lines, and we would be able to see that some effort went into localization.
The clips featured in this trailer have no subtitles, no voice-mouth sychronization, and no English audio beyond Master Xehanort's three lines. Looking at it, you can see that someone with basic editing software could have made this; I've seen similar editing jobs made with Windows Movie Maker. So, from what I can see, this is only a little placeholder trailer made by Gamestop so as to have something accompanying BBS on its page in their store.