This happened to me.
I had a Oneplus 7 Pro. I turned 3G off before the shutdown and it was fine.
Then Optus decided to brick my device because my phone wasn't on their list of compatible devices.
Fucking assholes.
I then put a friends Telstra sim in the phone to see if it would work, and it was bricked on the Telstra network too.
Apparently I could roll the phone back two android versions, install a ROM I don't want, give it root privileges which I don't want, and fuck around with adb to make it work, but I shouldn't fucking have to.
There should be a class action lawsuit for this shit. My phone was only five years old and worked fine.
Thanks for turning what I assume is tens of thousands of phones into e-waste so some dickhead with the latest 5G iPhone can take up an extra kilobit of bandwidth.
Happened two months ago, but I'm still mad.
Am I missing something? Or did they just admit they shut down 3G for nothing.