When it was added to current, I've even sysupgraded to snapshot just to test it. The setup is very straightforward, clean and easy, just like OBSD in general
Yup! Pretty exciting indeed. Now OpenBSD has first class support for WireGuard, out of the box. And all the usual tools such as wg(8) and wg-quick(8) work too.
Were those imported into the base system?
I ask because I see that the wireguard-tools package (which contained just those two binaries) still exists for 6.8.
Nope. Keep in mind you don't need those tools to use wg. Wg was integrated in such a way that you use it with the normal tools like ifconfig