Data point:

My status is only Gold. I applied through a link posted on a blog mentioned earlier in this thread as I did not get an email. Was approved before Hyatt admitted the offer of Diamond was an error. Yesterday I emailed GP for clarification on what level of membership I would be getting since the link I used stated I would be getting Diamond as long as I had the card. Heard back today saying I would only be granted Platinum level. Just logged into my Hyatt account and I indeed am Platinum.

This is what I expected and even though I was hoping for Diamond I understand why I am not. This makes sense and even though I probably wouldn't have applied for the Hyatt Credit Card if this offer wasn't out there, I figured it was worth a chance since I would have applied for this card in a few months during my next set of apps anyway.