This is not a Toss-Up, polls are not suddenly right when we like the results. Likely D, will be closer than it should be, but unless we're headed for a complete wipeout of the Democratic Party, McAuliffe will win.
I feel like this is way too hyperbolic. Republicans easily swept the non-federal races in VA and NJ in 2009 and it didn’t exactly translate into them winning federal races in deep blue and in many cases even light blue states in November 2010. Republicans barely winning VA wouldn’t exactly foreshadow a 2010-style wipeout in the House either (there are not nearly as many D-held Trump districts for them to pick off as there were D-held McCain seats in 2010).
People would do well to remember that this is still a gubernatorial election and not a national race, so Youngkin running against the literal embodiment of a shady career politician/out-of-touch D state party that has moved way to the left while largely avoiding national issues himself is obviously going to be a more effective playbook at the local level.
There’s a real danger of overinterpreting these results regardless of which party emerges victorious or what the final margin is, and I’d caution against predicting a Republican tsunami even if Republicans narrowly flip the state (or lose only narrowly) or vice versa. One thing that should be pretty clear, however, is that Youngkin is hardly the 'awful' candidate Demoratic partisans have made him out to be (this was always a silly take, obviously).