This quote leads me to believe that FreeBSD has something built-in the base or kernel that would provide most of the needed functions automatically, and there is no need to install PCRE. But before I start taking things for-granted I better ask ...
Would this apply to FreeBSD also?
https://calomel.org/nginx.html
Would this apply to FreeBSD also?
You need to make sure that the package for PCRE is installed when using OpenBSD. Use the command "pkg_add -i pcre" to install from your chosen PKG_PATH repository. BTW, you may want to also look at the Perl script pkg_find for OpenBSD package management.
https://calomel.org/nginx.html