I don't know that means Bluetooth will be running when the device is off. "Specialized hardware" could mean a full Bluetooth modem on backup power, but more likely it's means there's a low power beacon. Would be interesting if anyone does a teardown of the Pixel 8.
For non-Pixel 8 devices, definitely not. I assume "Offline" refers to the case where your device doesn't have WiFi/LTE, but can still use Bluetooth to communicate with devices that do.
I also couldn't find a mention, and it definitely does not make sense (and likely isn't even possible) to run Bluetooth without Android itself running
...which uses a crowdsourced device-locating network to help you find your lost or misplaced devices and belongings quickly – even when they’re offline.
Maybe this line is being misinterpreted?
Lunduke is such a contrarian. He cannot help himself from trying to argue that he understands better than common opinion, whether or not his position makes sense.
This is the man who disabled HTTPS on his site because he felt that the fact certificates can expire and domains can change hands made it not secure enough... and that using plain HTTP was somehow a more pragmatic security approach.
Looks like the original creator had a change of heart and has taken it down.