If they were to decide to do so, It would be much later in development when the engine core is more complete. It's still far too early in development, realistically speaking. There's still a lot of underlying framework changes taking place such as C++ conversion and DX upgrade.
Classic FPSC went through a real renaissance when the source was released and modders started doing their things but that wasn't until maybe 2/3 of the way through it's lifecycle.
I wouldn't expect them to even consider it until they are pretty settled and happy with the base product.
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