Just in case the downvotes didn't answer your question: no. Memory was already zeroed out before it crossed process boundaries. Apple's recent change is about

Just in case the downvotes didn't answer your question: no. Memory was already zeroed out before it crossed process boundaries. Apple's recent change is about zeroing it out even before it's reused within a process. (Freeing memory doesn't always give it back to the operating system; the userland allocator usually keeps a list of free blocks to be reused quickly.) Therefore, the attack you are describing doesn't work.