Let me start this off by stating that I do not believe that this was the original intent of the series. Given that Johnathan Majors was still prominent in season 2, this wouldn't make a lot of sense. I don't know the exact timing of the situation, but I'm assuming that the series was filmed before whatever issue is going on with Majors. (Honestly I don't even know what happened with him, I just know there's a lot of speculation of Disney moving forward without him. But that's not the point of this post).

If they really are making plans for removing him from the mcu, the most obvious path is just recasting Kang, but I feel like this could be another option. And it would pay off the story point that both He Who Remains and Ouroboros influenced each other in forming the TVA in a sort of time loop. The variant of Ouroboros that we know is very kind, but that doesn't mean that all variants are. He was shown to excel in understanding the science behind the tva, so it's not really a leap to assume that he is capable of anything that Kang would be capable of.