Apple did reportedly reserve all the initial 5nm capacity but I don't think we can say that's the reason AMD are still on 7nm. The early state of any node better lends itself to lower power, small SoCs. AMD may have been offered some capacity and turned it down because they prefer a more mature process for their larger chips with high-speed IO. Given the shortages now maybe with hindsight they regret that - who knows.

Zen 3 laptops haven't even been properly announced and are definitely not shipping. Even the Zen 2 models are in very short supply. Desktop Zen 3 is what is shipping and quantities are very limited as demand is very high.

You can order Asus Zen3 laptops such as ROG Zephyrus on Amazon today.

I stand corrected. Seems like the 35W chips have indeed shipped. I've been waiting for the 15W parts to reach the Lenovo range.The part they'll use was only even announced a month ago. Even within those some of the 5000 generation are Zen 2 parts. Desktop has been out for much longer across the whole range but availability seems quite poor.