I've been thinking a lot lately about the season finale of Loki and I've come to the conclusion that it didn't matter what Loki/Sylvie's choice was, the timeline was screwed and "Evil" Kang would have come into power. And I also think "Good" Kang had no way of knowing or stopping this.
Sylvie pushes Loki through a portal into the TVA BEFORE she kills "Good" Kang, but the TVA Loki lands in is already ruled by "Evil" Kang. There was no "reset" moment for him and he noticed nothing after landing so I don't see how the TVA could have been changed after he was there.
If that's the case then that means that the TVA had already been replaced at that time. I suspect the moment the timeline split and "Good" Kang no longer knew what was going to happen is when things changed.
In the void where Kang's castle is, they are outside of the timeline, in a seemingly 4th dimensional space with all of time running around them. As soon as a branch happens from that point of view, the entirety of that timeline has already played out - and "Evil" Kang wins the fight against the others, setting up his own TVA.
"Good" Kang could not have done anything to stop this or known it would happen. He knew exactly what Loki/Sylvie would do up until the point that he gave them the choice. If he can see all of time (or relive time through loops, or whatever the explanation is) then he would know exactly what happens up until he hands the reigns over to someone else. So he couldn't have foreseen that in doing so it would lead to an immediate takeover by "Evil" Kang.
I think "Good" Kang actually did hand over the power with "Good" intentions so he could retire. He did not know "Evil" Kang would be released. He also could not have stopped "Evil" Kang from being released because with infinite possible timelines there will always be at least one with an "Evil" Kang.
So It doesn't matter what Loki or Sylvie did. As soon as "Good" Kang stopped controlling the timeline everything was screwed. Or at least that's how I processed it.