Shouldn't actually be that fast. what's been built into the brand and what all?
that the chain rattles immediately after an oil change is normal, if the oil pressure is not yet there because the oil filter housing must be full first. This takes just 2-3 seconds and in time the chain rattles.
afterwards or at the 2nd start it should be quiet, unless the engine is again longer, e.g. overnight, then it can rattle for a short time.
The best way to identify a lengthened chain is when it is warm, idling or when it is parked; then it must not rattle, rattle or hit.