I don't think the changes they are doing at the moment have much security value. They aren't working on fixing OpenSSL security flaws. They are obliterating all the layers of cross-platform compatibility that make the code more complex, and removing everything OpenBSD isn't likely to use.

They are transforming a local copy of openssl that tracks upstream changes to their own fork, that probably won't reunite with the upstream version anytime soon.

In the process, they are obviously likely to find some bugs (and they already have fixed one or two harmless ones), but I think they are more interested in building a clean fork for themselves than in fixing the upstream openssl.