Murphy breaks a trend going back to 1977 of a Democratic governor not winning reelection in New Jersey.
Youngkin maintains a trend going back to 1981 (save for 2013) of the governorship going to the candidate of the party not holding the White House.
In both cases though these historical nuggets obscure big swings. Virginia is shifting D+10 in 2020 to R+~2. New Jersey is shifting D+16 in 2020 to D+~2.
Fwiw Biden's approval rating has declined about 12 points from 2020's popular vote margin and is now an 8 point margin of disapproval. So maybe these races are being dominated by national sentiment more than we would like to think.