My gut feeling is that it probably has been serviced at some time but that there aren't any records available. Who was the first owner? - some (although probably far fewer than used to be the case) fleets/companies still maintain their own cars but as to what records are kept, who knows. An 'onboard' record, if it is retrievable, would only show the information entered by whoever did it to reset it, that's not proof of what's been done, if anything.
Buying it when it's been advertised as 'no history' is a punt. If it transpires that it has been serviced, you win. If it doesn't have any history, you have exactly what you bought and expected.
These examples of 'no history' are becoming quite common since companies introduced digital service records, just hope that it's easier to access your money from a financial institution etc. in years to come when they say 'no record of that account, sir' (I've experience of it, eventually an old paper record proved them wrong, but not their fault [their explanation], just their legacy system!) I digress.
