That doesn’t seem to be the current Apple style anymore. And even if Cook did it, he just doesn’t have the gravitas that Jobs had. With Jobs, he could make the “one more thing” as if it was really a surprise. On Cook’s keynote, everything he said and his tone seems overly flat and scripted without genuine enthusiasm nor excitement. The “one more thing” will feel just like a regular announcement instead of a real surprise.
Now I wonder what would happen if Craig was the one doing the one more thing. He seemed to be the only exec left (since Phil is gone already) that can still show that genuine excitement instead of acting by the script. The rest of the speakers in recent keynotes were simply talking fast trying to finish their script.