My own expectation is regardless of who "wins" in November, the other side is going to accuse the other side of cheating. Biden has already said as much, that the only way he can lose is through "chicanery." Which I guess means he's now announced the only electoral outcome he will now accept is victory on his part.
While also declaring the American People "don't need to know" what his intentions may be regarding the Supreme Court.

Which actually leaves Trump's "we'll see" seeming downright mild by comparison.
If Trump loses, the only thing to be said about that is that Trump has nobody to blame but himself, all of the leading indicators say he should have otherwise won this cycle. I could
fully understand why people wouldn't want to vote for him.
Of course, the wild card in the mix is stuff that currently hasn't yet come to our attention(re: potential fraud). I certainly expect there is going to be all kinds of reporting about "balloting irregularities" which impact both sides of the political spectrum, with likewise biased reporting about such findings.
A Biden landslide is omnious for other reasons should it happen, as they may take that for "a mandate" much like Obama did(unless he's given a Republican Senate to fight with at the very least), and based on some of the things they promised during the Primaries, that could very well mean Civil War before 2022.
Not that a Trump win is much more cheery, as that could mean Civil War by January.
But I think the "shy voter" scenario is going to be in play in spades, and it is actually much worse than current attempts to esitimate it indicate. Which means Democrats are going to be crying all kinds of foul about the election results from in-person voting not matching up with their own polling results within anything close to the margin of error, unlike last time(2016).