4. A normal level of risk aversion in one of the most risk averse industries

If airlines ignored every threat that was “probably not” a real threat, they’d ignore all of them. It’s better to inconvenience a few thousand passengers than it is to kill a few hundred.

How many threats did actually turn out to be real to date? I couldn't find this being published. But how many threats did happen without any indication (only after the perpetrators tell). I can easily recalled maybe 3-4 incidents. So the issue here is do knowing threats really help?

There was literally no threat.

In the simplest possible terms: this is total bullshit security theatre. At no point has there ever been a bomb or even a bomb threat carried out via usb device names. There is absolutely no reason to even look at the names of Bluetooth devices on a flight.