Was that written only in his poster?
In the scans redon posted from that magazine, we somehow identified a red mark over Buggy's poster and people thought the same mark could be seen on Crocodile and Jinbe's posters.
If that's the case, I assume it only means those are the bounties that were raised after the Impel Down and Marinford incidents (and we would also see that mark on Daz Bones, Galdino, Ivankov and Inazuma if their bounties were visible).
Not that it would mean he didn't became a Shichibukai, but would mean this "under review" has nothing to do with it.
i think jimbei's wanted poster was stamped with under review too but im not entirely sure at this point. all the other strawhats bounties remained the same.
@kirjava tickets are not too hard to get so i wouldnt worry about not being able to obtain them. you might have to settle with a time slot you dont want though.
@tjalling i dont know if there's a video online… they were strict about no cameras allowed