Timing Chain oiler bolt

^^^^ Yes it is when it puddles in the lifter galley.Some engines had them some didn't.
Some had just the bolt with the hole and some had the bolt with hole and also a drip tab that the oil would drip directly on the chain.
Do you need it ? No, but it is of extra insurance that the chain and gears are getting oil.
The oil slinger on the crank snout keeps excess oil from flooding the front seal at the same time oiling the crank gear thus the chain and cam gear.
I drilled mine on my last 2 engines and made a drip tab.