What they did in this demo is collect a bunch of small demos, small enough that earlier models could have answered questions about them, or dinked them, individ

What they did in this demo is collect a bunch of small demos, small enough that earlier models could have answered questions about them, or dinked them, individually, and mostly demonstrated that the model could figure out which demo was pertinent to the question that they were asking, and focus only on that. But the input was still divisible into self-contained little bits -- so this is still somewhat different from dumping the full source code for a database engine into it, and having it answer questions about, say, where foreign key constraints are implemented -- or, more dramatically, how several different parts of the codebase work together to implement, say, transaction isolation levels.