As a matter of fact, any implementation of the same algorithm has the same parallelizing possibilities. You just need a smart enough compiler.
But a "smart enough compiler" is what compiler people say when they are talking about their version of the abstract anthropogenic equivalent AI. The fact is that the first one is much easier to parallelize, so that real implementations actually do it, while the second one is not done on practice. And it's easier to parallelize because there are some extra guarantees on the signature of those functions that a for loop does not give.
But a "smart enough compiler" is what compiler people say when they are talking about their version of the abstract anthropogenic equivalent AI. The fact is that the first one is much easier to parallelize, so that real implementations actually do it, while the second one is not done on practice. And it's easier to parallelize because there are some extra guarantees on the signature of those functions that a for loop does not give.