Hyatt Gold Passport - Online Check-In

Can someone summarize the benefits of Online Check-in? I recently used it one morning to ensure I had a room since I was checking in past midnight that day (in actuality the next day). I received an e-mail almost immediately stating I had “checked in”; however, it also stated that another e-mail would be sent with my room number when it became available. At about midnight, I received an e-mail that my room was ready. Did that mean my room wasn’t allotted to me until that point and I ran a greater risk of being walked? The e-mail didn’t even provide me with a room number. In the future, should I always state that I will be checking in at 3:00 p.m. instead?

Hyatt used to have 1-800-Checkin, where the person on the other end would communicate directly with the hotel. I've used that when I knew I'd be quite late and wanted to make sure I really had a room.

I would suggest using that in the future (does it still exist?), or calling the hotel directly.

(However, even that doesn't always work. My wife and daughter got walked from the Ritz Carlton in DC when arriving well after midnight, even though I called the hotel several times in advance the day of their arrival.)