Trivially, you can get Turing completeness out of a Turing machine, which does not have these features, so no, it is not accurate to say they're absolutely necessary. There's a practical side to this, though. What sort of syntactic conveniences should you provide such that anyone might actually want to use your language? That's probably what it should say. The mov instruction is Turing complete, but you likely want some higher level of abstraction that allows for things like developer ergonomics, the possibility of type checking, allowing for human readable source code.