I think we're reading too much into it, the law reads 2020 earned income is less than 2019, zero is less than. 

I don't see anything that says they must qualify for EIC based on 2020 earned income before using 2019 earned income is an option.

So unless we see any more IRS guidance about this in the next couple of weeks, I'm going to take it at face value, zero is less than any other figure.