Single shot Pcps that later have multishot capability a marketing move?

I've always wondered why there are guns that are single shot loading when there are other models that appear to be built off the same platform that are magazine fed. I don't know the deep history of Pcps but I feel like this is the Golden Era of innovation and evolution for airgunning.

So, Why do some guns get released as a multishot later after starting out as a single shot? I'm not an engineer or a tinkerer so it's just an honest question. I wonder what the goal is for doing it this way and if the reasons relate to testing the market's demand for the gun first.