I think these attacks are theoretically real. I don't think these specific instances of the attack as described by Bloomberg are real. The only plausible scena

I think these attacks are theoretically real. I don't think these specific instances of the attack as described by Bloomberg are real. The only plausible scenario in which none of Bloomberg, Apple, and Amazon are knowingly lying is one in which only a select few employees at Apple/Amazon knew about this and were talking to the FBI, as you suggested. Except this doesn't make sense. The only way in which a select few employees would know about this and nobody else is if these employees are subject to a gag order. But the only way they could be subject to a gag order is if the government came to them in the first place, said "here's a gag order, now that you have it I'll tell you about the attack". But according to Bloomberg, a random spot check by Apple employees found the chip, and IIRC they said a third-party security audit ordered by Amazon found the chip on the Elemental servers. In both cases, this attack would have been immediately reported up to the highest levels at the company prior to even beginning talks with the FBI. There's no scenario in which an employee at Apple or Amazon was made aware of the attack, reached out to the FBI, and received a gag order, prior to notifying their superiors and having the information make it all the way up to the executive level. Of course, you could claim that Bloomberg was wrong about how the chip was found and right about everything else, but that's not really plausible. Why would they be wrong about that and right about everything else? How would it even be possible for the government to have determined that Apple and Amazon had their hardware compromised without Apple and Amazon's knowing cooperation? The government doesn't have access to these servers, only Apple and Amazon do.