And ... all of this seems like a lot of machinations to avoid a $140 fee for a visa allowing multiple entries over 10 years. It's not as if this is a huge fee or a complicatged process.
Think of it as travel insurance. No need to argue with gate agents over interpretations of Timatic which has occurred on several European and US airlines. Plus, it gives time to work through any complications for travel into China since not every law abiding US citizen will be granted a Chinese visa. Better to know that now rather than when standing in line at PVG immigration.
And, I'll add that I'm old enough to have enjoyed sneaking across the French border without a visa during the years it was required. Then I realized, just pay the money and get the stamp and not worry about getting kicked out of a country.