what makes you say that he wouldn’t?

Because he seems like a no-bullshit kind of guy when it comes to the OS he started. I don't see him kicking Russians off the OpenBSD project just because that is the politically expedient. OpenBSD always chooses to do what is better for security than what is popular. This means they focus on the technical aspects, and don't care about the political ramifications of their decisions.

He also went to a ruBSD conference in 2014. http://undeadly.org/cgi?action=article&sid=20140115054839

This is his personal website: https://theos.com/deraadt/

OpenBSD doesn't have a Code of Conduct either, because the project is run by "old school" techies/computer nerds who don't need a document to tell them racism or homophobia is bad and that people who work on a project together shouldn't insult one another based on characteristics that have nothing to do with the person's ability to code. So if Theo/OpenBSD didn't follow the latest CoC fad, it's unlikely they will go for the Russia hate fad.

For comparison, this is the Linux Foundation's Code of Conduct:

2. Never harass or bully anyone verbally, physically or sexually.

3. Never discriminate on the basis of personal characteristics or group membership.

They should have added a caveat for Russians. Further proof that CoC is about control over others. It's obvious that leaders of projects don't need to abide by the CoC.