BuddyPress.org

If I understand correctly it does not matter which licensing type they use because as soon as they use WP code it becomes GPL. At least that’s what a read here:

Interesting WordPress GPL implications

This means that whenever a theme or a plugin uses just one function from the WordPress code, GPL license automatically ‘kicks in’ and takes over. And since plugins and themes must use WordPress functions they automatically become GPL as well.

Can someone confirm this is correct?