Visa free is arrival and departure airlines are different?

Hi! In relation to eligibility for this visa for Shanghai, does the airline that I would arrive in on have to be the same one that I leave with?

So say I fly from Dubai to Shanghai with Emirates and bought an onward one way ticket from Shanghai to somewhere like Hong Kong with another airline like China Eastern, is this okay?

Or would I have to purchase a multi city flight with the same airline to be eligible for the 6 day free transit?
Thanks!
Brian