However, it's important to note that although the sources for RHEL packages are available as open-source, that still doesn't make CentOS an exact replica of RHEL, and therefore doesn't make RHEL itself "free".

RHEL 8 was released almost 4 months ago and there's no CentOS 8 yet. Mainly because taking the "free" RHEL sources and rebuild them isn't a simple case of removing logos and other "non-free" material. The build process itself (the sequence in which packages must be built so that all of them build successfully and with equivalent functionality to RHEL) is a major piece of what makes RHEL, RHEL, and that isn't free (or even publicly available).

Free as in Freedom to download CentOS

no really free as in free beer