Ah... interesting, a bit of GPT-research tells me that in Russia font shapes can by copyrighted, but no so in the United States, which I had assumed was the common rule world-wide.

The key points are that this was a lawsuit by a rival candidate, not Microsoft, and was overturned by a court of appeals because it was without merit: the candidate Mikhail Matveyev used the Arial and Tahoma fonts in a report linked from his campaign website, which the court deemed not to be part of his campaign materials. Not to mention that having a license for either Office or Windows will give grant the rights to use those two fonts!

In other words a rival tried and failed to get him on an invalid technicality.