Of course, but any of those people making a copy of the code can be the ones to decide to build a community around it.

Fabrice Bellard doesn't need to personally administer to the ongoing development and community functions of QEMU or ffmpeg, it is sufficient that he released the code as open source, and others carry the torch from there.

And if people disagree about the form those communities take, they can split them as they see fit. As happened with libav and ffmpeg for a number of years. This too is fine, and is only possible because of the license.