It's supposed to come from that hollow bolt. Most everybody throws the thing away. If you look in the How To section,
@krazykuda Karl has a write up on it I believe. It's a factory modification. I don't know when they started doing it, but I've torn down lots that were factory engines with that mod done. No way would I put one together without it. To answer your question more directly, no, there is no "purposed" oiling of the timing chain without that. It just "gets what it gets". If you can improve upon that with one drilled hole, why not do it?
