OW2 was announced as free-to-play and would shut down the original Overwatch servers with it. However, Blizz had said that OW2 would come with a PvE mode (which was highly requested with Overwatch). When OW2 released, the game released with no PvE mode but the promise that they'd add it in later. In May, Blizz announced that the PvE mode had been cancelled altogether. A week or so later, Blizz reversed the decision to cancel the PvE mode. Now the PvE mode is coming and it'll cost $15.

So, just more Blizzard being incredibly shitty. As always.