The teaser which BioWare put out didn't come out and tell us much that we didn't already know. Or, at least that's how it appeared on the surface. An enterprising SWTOR player dug deeper and discovered some interesting imagery used in the video.
Specifically, the weapons seen in the background seem to match that of the Massassi race as seen in a Timeline video. This race was seen on the moon Yavin 4. There's some debate on the forums, of course. But it is an interesting observation. From the reddit comments, it was pointed out that the Sith Inquisitor receives a mail after Forged Alliances which foreshadows a moon.
So we don't know anything for sure, but it seems like Yavin 4 is a good possibility. We also don't know what kind of experience it would be, a whole planet? Just a daily area or operation? Could be anything. Yavin 4 holds a lot of significance in the SWTOR lore, so I'd look forward to exploring it.
Alaloth - Released
2 hours ago