I think it more likely has to do with Far Cry 3 and Splinter Cell: Blacklist being in the bundle and all of those games being in the "Ubisoft Prime Pack". Other non-Prime Pack Ubisoft games aren't registering as being in the bundle.
I had that problem, and all I had to do was click the "view email in browser" link, and that gave me my key. So I'd suggest anybody else who has the missing key problem try that before emailing Carl.
There's certainly precedence for at least some publishers/developers thinking that- that's the reason you saw online passes and other things that basically required that you either buy the game new or pay the publisher some fee in order to use part of the game. It's a big part of the reason...
They have this. It's not in stock currently, but it's possible it'll come back in time for Easter.
As far as Square and Ubisoft goes, I'm not going to get too excited by deals that haven't been posted yet. That said, if either Tomb Raider or Far Cry 3 drop below $5 post EC, i'll probably get them.
Getting the DLC now means that you've basically used an EC coupon to save $2. I mean, if you have plenty of them, then, sure, it probably doesn't matter. But it might be smart to wait until the end of the month when we'll know what the rest of the sales will be and whether or not you'd rather...
1/1/2014 to 1/3/2014 Injustice: Gods Among Us Ultimate Edition - $19.99
It's on the sales list compiled by asheskitty linked to in the OP, in case you're wondering where I got that info.
Now that I feel pleased with myself for actually catching one of these glitches, I'm pretty sure Don't Starve is going to be in the next Humble Bundle's dollar tier.