Am I missing some subtext or something, or is there just no real info here? "They did a horrible thing, but I won't explain the nuances behind the situation, and you're just going to have to take my word that it's awful!"
Whatever drama this is referring to aside, Dead Cells got a ton of post-launch support and really, I don't think anyone could possibly be upset by the amount of content the game has, or content updates it received. Sébastien seems to believe that that's not the case, so maybe they had some great stuff planned that was never realized? Or maybe they simply couldn't justify the cost of continued development for an older game from a studio that has a new game in the works? I don't know, because the article doesn't tell us.