Let's call a spade a spade,they saw an opportunity to get more money for 0 extra effort(at least that was the plan),and went for it
This. It's exactly the same shenanigans that went on, when VBulletin was bought out years ago.
At least there are lot's more alternative panel solutions today, than there were forum solutions back then.
CPanel will feel the burn a good ways down the road. Going to take time but it will happen. Prob is that by then, they would have made their cash, exit, and move on.