Indeed you can't install linux on that machine, but that's a technical problem and a deficiency in Lenovo's setup, just not a conspiracy by Microsoft.
The actual reason, some technical firmware/driver minutiae, is exactly the kind of reason that both makes sense and I would not expect a PR rep to know or be able to explain.
That may even be what happened here. They were told "It's happening because we're using Windows X and this makes it runs better". That becomes "It was because that's what Windows needs" or "That's what Microsoft has us do".
The first one is accurate but misleading, the second inaccurate. But I could see either one resulting from that conversation.
Now if the Lenovo rep could cite the rule that MS (supposedly) gave that says "Do things way X" then I would believe them. But "because Windows" alone isn't very compelling.