I got a place on the 512GB with Controller list, and got an email a few days after they started. I ordered it on Friday the 3rd and got it today on Thursday the 9th. The tracking codes were all over the place and gave different estimates depending which branch of each company I used. Steam claimed it was shipped when the courier said they hadn’t got it so I was worried for a few days. But this morning Royal Mail (UK customer) sent me an email saying it would arrive today, while GLS said it would arrive tomorrow.
Safe to say I’m happy to have it now and be playing games!
that was the subject line for the “you have 72 hours” email.
Additionally it shows up in your steam cart until you buy it or remove it. I had a game in my cart and went into the cart a day later and they were both in there.