Hm, just watched a video of the Seraphim Vault on the beta, and behold it is there in most of its current form. If I had to guess, I'd say the missions are (at least until The House of Wolves) already done. But, the update was 2.4GB, that had to be something, I'd say it was probably the cinematic, the gear and the raid, as well as the sound files. So while I was slightly misinformed, I wouldn't say I was completely.