The news media is calling Jack Smith's filing on Trump’s 2020 election plot an "October Surprise". I don't think so. For anybody paying any attention it's a total non-surprise.
There are three basic voter blocs this election.
Group 1. Pro-democracy, reality-based, informed voters
Group 2. Low-information voters, often undecided voters
Group 3. Cultists
Groups 1 and 3 are unsurprised by the revelations in Jack Smith's latest report on Trump's efforts to subvert democracy. Group 1 is again aghast and disgusted. Group 3 again accepts and perhaps approves of Trump's efforts to cheat the voters, as long as it is other voters.
Group 2 was barely aware of Trump's impeachments, the events of J6, the J6 hearings, Trump's trials and convictions or much news at all. Jack's Smith latest documentation of Trump's crimes barely registers with them. Many of them won't vote. For the few that do vote, the news won't matter.
This so-called October surprise will dissuade very few of group 3 for voting for Trump as they have already forgiven him for his long list of crimes or they don't believe he did any of them.
They only group that might be impacted by the news is group 1. It gives them another reason and another reminder that their vote is important.