I wonder why there wasn't a confirmation that he is a companion. He is a LI so that would make sense, right? Unless he is a LI NPC.
...
Now, that would be too good to be true...
Really, there are several reason why they might not have announced him being a companion.
1) He's next up for Follower Friday, so they're keeping the suspense until then.
2) Saying he's a companion might expose something else, like the Grey Warden being a rogue now or out, etc.
3) They don't want to, because they are trolls.
And a few reasons why they wouldn't confirm him as an NPC romance.
1) That announces NPC romances, which they might not want to do yet.
2) Confirming Cullen as NPC all but confirms the Grey Warden as a companion.
3) Trolls. The lot of them. 