The episode is probably going to alternate between Mako telling Wu some of their stories and flashbacks of Varrick, with some plot development in between, judging by that new shot of Korra in that promo. Oliver Sava is hinting that fans aren't going to like it because something sad or unhappy happens, not because of how bad the episode is.
It's definitely not getting canceled, come on. Bryan and Mike just came back from finishing animation in Seoul.
Oh, and didn't get a chance to comment of the last episode, "Reunion." Was better than I expected, although the reunion itself could've been better, I guess. I don't know, they greeted each other like casual friends, not like a team that has been through almost-armagedon together... But at the same time, it seemed normal to me?
Varrick and Bolin were great, so if "Remembrances" gives us a Varrick flashback and that's it, I'm happy. They've been doing great work with Varrick and Bolin so far.
EDIT: I'll confess I stayed out of KorraGAF on purpose... I was on vacation, and that included getting away from routine things, like bickering on this thread XD haha, sorry guys. I scanned some of the comments after "Reunion" aired and that's it.