Benchmark MATLAB & Julia for Matrix Operations

No it is not.
It is optimized if you explicitly loop on its elements. Since it is one time use there is no gain in that as it is allocated in the assignment.
Whats happening is allocation and pointer naming. Exactly as if I did pre allocation and use fused assignment.

Moreover, it is the same as in MATLAB. Since the idea here is to compare to MATLAB on Linear Algebra related operations, there is no real issues here.