They were looking for head to head data in a random sampling, and they proposed the matchups with the GOP candidates who are getting the most mention. I don't know if someone like Ossoff would have the national name recognition that Newsom or AOC or Harris have.
There's been a shift in Democratic strategy, and a better chance for Democrats to win based on issues, rather than just on national disgust with Trump. But there's also been a very obvious shift in the mindset of voters in the electorate, who are easily duped by a press that is no longer free, and by ignorance because the education they've received no longer adequately teaches critical thinking associated with American History and Civics. Republican influence in the states has reduced social studies requirements to their lowest level in decades. The OP indicates this:
An Ideological Shift Has Occurred
The fact that someone like Trump, and the tangled confusion of MAGA ignorance and incompetence when it comes to determining what is important in American politics, is an indication that major reform must occur soon. We have lost our free press and the government now must be more than just pro-active in making sure conditions exist for getting it back. Whatever steps are necessary to break up the billionaire monopolies which control the companies that own television networks, internet communications, radio broadcasts and the online "newspaper" business must be taken. The structure is there, constitutionally and in the law. It must now be strictly enforced.
We also have a public education system that was considered essential for the support of a free, democratic society. But far too many Americans are ignorant when it comes to defining and understanding what democracy is, and how it works for all Americans, and that's because the requirements for school-aged children and youth to learn about it in school have been gutted from graduation requirements. We need to restore strong standards in social studies education that put how constitutional democracy works in front of students every year they are in school. Two years of American history and a half year of Civics, shared with a semester of economics is not enough.