'None of the actors can be taken at face value, particularly with national security implications.'
#1. The Reg article missed a few things. For starters there were Bloomberg companion reports covering the thorny issue of outright-denial regarding the risk of potential Securities-Fraud:
#2. Some of the chips were better hidden. Also there might have been more controls and tests on the critical chips, making it more risky to package them as a single integrated circuit, plus its more costly: "In one case, the malicious chips were thin enough that they’d been embedded between the layers of fiberglass onto which the other components were attached, according to one person who saw pictures of the chips. That generation of chips was smaller than a sharpened pencil tip, the person says."
#3. Who stands to gain from the publicity, who stands to get hurt? My own take... The US has done similar sneaky things so its almost certain that China has. The difference is, China has exceptional domestic leverage and could interfere at source, whereas the US doesn't have that level of control. But overall being a huge national security issue and potential shock to the US Cloud industry, its almost certain big tech would have been told to keep quiet and indemnified from any markets issues. But I also believe some elements in the US Govt wanted this to come out now that there's a Trade War... It might cause an Offshoring of manufacturing away from China, which could severely hurt.