From what I've heard this is the largest test like this they've ever done, at the same time across all time zones, and the first time doing it on the 5G frequencies, so that's why people are concerned.

They did the same thing in 2011. It was a shitshow because the network was primarily built with station to station relays. The newer system is actually far easier to implement because broadcast features are always required to make any cellular system function and EAS delivery happens through IPAWS now.

IPAWS is essentially just an FTP server where providers log in and check for any active alerts. Finding one, it downloads it, then broadcasts it. They're essentially testing onboarding a bunch of new providers who otherwise don't receive messages.

Radio stations have been using IPAWS for years now and it works fine. They know full well this will work fine. There's no real reason to do it.