I remember similar articles being posted 20+ years ago on Slashdot. And as we’ve seen, it’s often less of a “use Linux” and more of a “we have an alternate vendor” and there’s often suspicious lock-in (see the case in the EU or some similar country where the vendor was reading emails).

At least in some cases, it's actually using Linux and open document format, e.g. https://en.wikipedia.org/wiki/GendBuntu