I wouldn't read too much into that for two reasons... NoVA is loaded this time around with many, many thousands of pissed-off parents of school-aged kids... and Youngkin strongly encouraged his backers to vote early. Very likely that high number is a more even mix than before.
Dems getting caught cheating now will reopen the 2020 election debate and they do not want that.
The vast majority of election fraud has already taken place. Based on my experience, there is very little fraud on election day. However, now that we know that the tabulating machines can be hacked and there are ways to shift votes thru the adjudication process, I remain agnostic about a Youngkin win. He needs a big margin to offset fraud.