Well, not only in their iPhones. And not in the same cloud storage provided by the phone. The only backups you really control are the ones in your possession, so you must keep offline local backups of anything really important to you.

The big marketing point of cloud storage was that you would not need to worry about owning and maintaining local storage, but they conveniently downplayed the fact that they could lock you out of your own files at their whim.

Actually in this case, the danger is in the cloud storage not the phone's. The user still can access/use his phone, just not the cloud-connected functionalities.

Only because Apple didn't remotely lock the phone as well, which they surely have the technical capability to do.

The data in his iPhone was not impacted.

His Apple cloud account was locked until the account representative unlocked it.

The physical device was not locked, bricked, or wiped. The situation was bad, but let’s stick to the facts

His iPhone could not sync, update, install new software, or send messages, nor could he sign out and use a new apple ID with it to restore that functionality. For a phone, this is effectively bricked.

Paris uses the term "bricked" in the original post: https://hey.paris/posts/appleid/