That letter is a conspiracy theory allegation with
no corroborating evidence from the moderator, the Biden camp, Presidential Debates Commission, or elsewhere. The conspiracy alleges that the nonpartisan debates commission rejected the moderator's right to choose the topics, but then gave them back to the moderator at the last moment in an effort to hurt Trump. Yeah, right.
You've repeatedly claimed that an alternate set of debate topics exist, but you allege that because I can't find them that it must be true? Similarly, you've alleged that Biden's campaign denying the conspiracy theory "made it likely more true."
Great! Now we can add
backwards reasoning to your long list of fallacies and conspiracy theory peddling. The onus isn't on me to find your imaginary debate topics list; I've already corroborated Lacius' argument that the "moderators choose the questions." Chris Wallace chose the topics for the first debate and Kirsten Welker chose the topics for the third debate. These are established facts. Wild allegations involving conspiracy against one of the candidates with no corroborating evidence does not a fact make.
Case closed.