An open source Carrara will be just as dead as the current closed source.

Blender, with tens of thousands of users around the world, can raise enough funds to support only a small team of full-time developers See Link..

Carrara has, at most, few hundreds of faithful users around the globe. It's extremely unlikely that it will ever attract enough interest and enough funding to sustain an open source development.

Let's face it: Carrara is a mostly dysfunctional buggy 3D app. And with inexperienced interns in charge of its development it will keep getting worse. Carrara can actually be viewed as only a 'Proof Of Concept', i.e. it gives you an idea of what a full-featured 3D app should do. But in no way is it a reliable platform for a production pipeline.

Don't even bother about the future of Carrara, because there is none. If the current version that you are using suits you well then keep using it until it no longer runs on your favorite OS, otherwise trash it and switch to something else.