Ossoff actually got less raw votes than the 2016 Democrat who ran against Price. Did he win some Republicans over? Probably. Did low information Democrats not turn out even though there was a bombardment of advertising? Unquestionably.
Good point. The Democrats appear to have a much lower ceiling among upscale college educated Republicans than they'd like to admit.
As far as I can tell, the whole point of that post was that the electorate in the special was much whiter and more full of Romney voters then in 2016.
80% of voters in 2016 voted in the 2017 runoff special election and the district itself is 72% white so to have it skew slightly whiter isn't that much of a surprise to anyone. But let's entertain the notion that somehow wealthy republicans are gonna start flocking to the Demcorats in large enough numbers (despite their lifeline voting habits, the hyper-polarized climate, Ossoff losing, voting against their own economic self interest, etc.) to somehow mitigate the Democratic Party's losses with WWC voters. Here's your problem:
The only way this strategy actually works is if you can get enough crossover votes from Republican voters to win in districts where the incumbent GOP candidate won by double digits. That's not happening. Whites without a college degree are far more swing-able than wealthy college whites.