Only if Trump loses by one vote in the deciding state, which is quite unlikely.
The problem isn't going to be Freepers not voting for Trump in the general election, because almost all of us will if he's the nominee. The problem is going to be the millions of other voters who don't vote for him for various reasons, undoubtedly including that they don't like his tone/level of civility.
And sure, it'll be "their fault" that he doesn't win. But I doubt they'll care given that they chose to not vote for him.
Trump “lost” by less than 43,000 votes across Ga, Wisc, and AZ in 2020. Nevertrumper Freepers and Rinos not voting for him was more than enough. The 81 million votes was made up of 2 million exra votes in NY and 5 million extra in CA, 2 states that don’t really count as they are always solid D. It was basically tied elsewhere.