More irresponsible use of data.
Even the articles you posted attribute the continued growth of the game to its eSports presence, and not necessarily the game itself. For anyone that has actually played, there isn't a whole lot of development to be done at this point. Most of it is in maintenance, maintaining balance and a steady stream of new champions and skins to maintain cash flows.
So again... if you could point to one development change that continued or spurred that growth I'll concede. You then have to determine his contribution to that change.
I mean if we are going to follow your logic, and attribute the growth of LoL to GC. Then likewise we can attribute the subscription decline of WoW to GC.