The simplest answer is usually the right answer...
Normally that's true, but in the spy-vs-spy world maybe not so much. Another saying goes: "Every answer begats two more questions". It would seem someone is/has been shoveling the pile, the questions are "who" and "why"?
From the article: Although a better explanation may be that it accurately reported a misinformation campaign put together by some part of the intelligence services.
That seems a simple explanation but I'll reserve judgment as there's still too much politics, etc. from the agencies to really know. If its a misinformation campaign to discredit the Chinese, then Super Micro is taking a huge hit in credibiity in a variation of a drive-by shooting and the company and the IT industry will suffer.
IF there's been mods to the board than why haven't any been produced for independent inspection? At this point, that would point back to the TLA's and "national security" excuses. The Rabbit Hole is getting deeper the longer this goes on.