I find that hard to believe but shall give you the benefit of the doubt GG
There's always a film of oil on the bores on any engine otherwise recip donks would have a life span of a few hrs at best:-)
Just for the record filling an engine via the normal filling point technically won't necessarily fill the bores if the rings/pistons are in good order. You would have to fill each pot via the spark plug opening. It would take an inordinate amount of effort to fill an engine completely with oil but would be worth it for extreme long term storage.
Wmk2
How do you think the film of oil gets on the bores to lubricate them? The same way pouring oil through the filler will fill the engine completely with oil including the cylinders.
The reason you do this is to prevent all the oil draining into the sump over time. Thence once you turn the engine over, you have to wait until the oil pump builds pressure and redistributes the oil to the head. In the mean time the pistons are grinding on the bores with minimal lubrication.