NSW Police to Be Given Powers to Access and Download Phone Content on the Beat
(www.sydneycriminallawyers.com.au)
The article is deliberately a lot of things imo, none of them good. It's not written by a lawyer btw, important to note that.
The point about the warrant is the only thing that matters here, and I'd argue it's meaningless when we are talking about lawful seizure.
A warrant provides you with the legal authority to search for the device, inside a private residence for example. When a cop witnesses a crime and sees that a device is relevant to that crime they can seize it without a warrant. In that case the idea of getting a warrant is superfluous and only a thing because the DEAO law explicitly says so.
They will still need to apply for the DEAO from the same kind of judicial officer that would sign their warrants to get into it.