No. From the document you cited: “ The Secure Enclave Processor runs an Apple-customized version of the L4 microkernel. It’s designed to operate efficiently at

No. From the document you cited: “ The Secure Enclave Processor runs an Apple-customized version of the L4 microkernel. It’s designed to operate efficiently at a lower clock speed that helps to protect it against clock and power attacks. The Secure Enclave Processor, starting with the A11 and S4, includes a memory-protected engine and encrypted memory with anti-replay capabilities, secure boot, a dedicated random number generator, and its own AES engine.” iOS still has an XNU kernel. L4 is a different beast entirely and being used for a different role here.