[billwilliams (OP)]

What will happen if organized basketball and football games are played in 2020-21?

high school-Suppose when the first football game and later basketball games are started, there are no players with COVID-19. (This is a big "if" because high schools can't be expected to test all of their basketball and football players for COVID-19, for various reasons.)

college-Suppose when the first football and later basketball games are started, there are no players with COVID-19. 

NBA-Suppose when the first basketball game is started, there are no players with COVID-19. The league can afford to test it's players as often as it wants.
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In my opinion, the first games of the season will go well. But that's it: it's inevitable that some players at all levels
are going to contract COVID-19. As of June 15, 2020, I don't know what expenses a hospital faces when testing one person. I also don't know what the "answer" to what each person tested is financially responsible for paying is.

I just know that the only COVID-19 test that I've had (I tested negative) resulted in an outpatient charge of $181.00 last week. But even that is out of the price range for high schools and even many 4-year colleges.

I'm sure that a lot of people who are sports fans in America are going to think, "Okay, but a healthy young athlete who is not overweight is not in danger of getting COVID-19."  However, almost all football players in America are probably overweight for their height, because they're encouraged to put on as much muscle as they can.

I don't know of any study that has proven that high school or college male athletes who are not overweight can't get COVID-19 during competition.

[Colin2B]

However, almost all football players in America are probably overweight for their height, because they're encouraged to put on as much muscle as they can.

I don't know of any study that has proven that high school or college male athletes who are not overweight can't get COVID-19 during competition.

Muscle weight is not a comorbidity for COVID19. It has long been recognised that muscular individuals give a high reading on the simple BMI scale even though they lack the dangerous belly fat.
Although the athletes are still at risk of getting COVID19, they do not (usually) have the underlying health issues that accompany obesity.