your question answered mine, one of the reasons I'll wait a while to install CentOS 8
I have BCM 4313, using the rpmfusion wl packages.
The RPMFusion el8 repo doesn't contain the broadcom akmod/kmod wl rpms yet, but you could
try installing the el7 rpms from here https://download1.rpmfusion.org/nonfree ... index.html
you'll need the broadcom-wl, akmod-wl and (current/running/uname -r) kernel-devel packages, they work with the latest elrepo mainline kernel (currently 5.3.2-1.el7.elrepo.x86_64) so I can't see the kernel version being a problem.
The broadcom-wl and akmod-wl rpms will need to be installed together then a reboot.
I know it's never a great idea to install rpms from different releases, but this sounds like you have a fresh install with no working wireless, so why not be the test pilot
Hopefully rpmfusion will have el8 rpms soon.
Let us know if you have success.