Cody was in WWE for years and was established before so why anyone would not know is ludicrous. KENTA was on 205 Live and no one cared so he is a perfect example.
They made a big thing about Jade signing which is the right thing to do, so that's what they should do with Okada if he end up there, regardless if he starts in NXT or not. I don't think Nakamura would have been received as well if he wasn't showcased in NXT like he was.
AJ made a name for himself in TNA for years as well. The only reason I feel he didn't go to NXT was because he knew how American TV wrestling was done, since he did it for so long in TNA. He was the only one that doubted himself, thinking no one would know him.
There will be plenty of people who have no idea who Okada is, but WWE is smart, they will let people know before they put him on TV.