It was kind of with it.
The blue post revealing the patch did not say about the customisation. But it did say about the questline and velen reuniting unlikely friends. (And thats turns out to be what unlocks it.)
And then later that night when the ptr patch notes came out, the customisation was mentioned (it was not available for testing) and dataminers found it straight away.
So it was vague for like 4 hours.