I for one am going through quite a culture shock. I always assumed the nature of FOSS software made it immune to be confined within the policies of nations; I guess if one day the government of USA starts to think that its a security concers for china to use and contribute to core opensource software created by its citizens or based in their boundaries, they might strongarm FOSS communities and projects to make their software exclude them in someway or worse declare GPL software a threat to national security.
Why do you think Linus is not being truthful?
Other countries are similarly sanctioned, and hundreds of maintainers from those sanctions are still there. So the sanctions thing is absolutely just an excuse.
What Linus just did to Russians is scaring a lot of people right now, who are probably wondering if they should keep working in association with a project which has just demonstrated its unreliability.