From the decription, that it’s long and narrow, something tells me that what we are dealing with amounts to a fragment of a much larger body. Most likely the result of a collision of two bodies, one of which just happened to fragment in just the right way. From the reported existence of organic molecules on it, I’m thinking it might be a piece of planetary crust, and that planet had life. ‘Oumuamua may have formed just through aggregation, but I find that highly unlikely, just too improbable.
This points to an interesting possibility, that there is life out there. Probably not all that advanced, but still.