If Russia, Inc. was a thing? Yeah maybe? If you're talking about just yandex, it's not securities fraud unless the executives had something to do with the invasion.
The joke is that pretty much anything that causes the stock to go down can be used as the basis of a securities fraud lawsuit. It's a recurring theme in his daily column.
I read his column, and I get the reference, but your characterization is incorrect. The stock going up/down needs to be caused by the company and/or its executives. For instance, "global warming causing the company to perform poorly" alone isn't securities fraud, but "global warming causing the company to perform poorly, and a few years before executives told shareholders global warming isn't real" is securities fraud.
They mentioned "geopolitical risks" in every prospectus they issued. So the answer is no - investors have been warned that this might happen!