It looks like anaconda isn’t installing CentOS-release-stream when you install CentOS 8 Stream. I just did a minimal install through PXE and it pulled everything from the 8-stream repository and installed the stream versions, but didn’t install CentOS-release-stream. (Below is the output of yum list \*release\* immediately after install.) This means that it will not get updates from stream. Is this intentional or is this a bug?
–Rich

Last metadata expiration check: 0:06:02 ago on Tue 22 Oct 2019 11:02:55 AM
PDT. Installed Packages CentOS-release.x86_64 8.0-0.1905.0.9.el8
@anaconda Available Packages CentOS-release.i686 8.0-0.1905.0.9.el8
BaseOS
CentOS-release-stream.x86_64 8.0-0.1905.0.9.el8
extras elrepo-release.noarch 8.0-2.el8.elrepo extras epel-release.noarch 8-5.el8
extras