True in the conflicts, Not true about the -free packages in relation to the -freeworld packages.
The packages from rpmfusion contain many codecs to allow access to different media where the codec is restricted from fedora distribution. The -free packages thus have limited codecs and one often finds that they are unable to access particular media as a result. Replacing the -free packages with the corresponding -freeworld packages gives one access to the full codec range that is otherwise not available.
Each user must choose what works for them.