This is the last I heard from a contact on the SuiteScript team:

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Hi Eric, I wanted to give you an update on this. Upon further discussion, we are delaying the decision of disallow creating new scripts in 1.0, this won’t happen anytime soon, if it happens at all. We are focusing on enhancing 2.0 and making it attractive, and figuring out ways to help people transition from 1.0 to 2.0, instead of just disallowing people to create scripts in 1.0.