A quick list of what I feel would be important issues for NHRA to promote any national event and Pomona easily meets all but the last one.
Potential of Profit vs. Loss
A very large marketing area population
Airport and Interstate Highways close to an easy to enter and exit track.
Facilities near track for racers and fans. (Hospital, hotels, campgrounds, restaurants, etc.)
Availability of large quantity of quality part time staffing.
Government and neighbor acceptance of increased traffic, motor racing, increased noise, environmental issues, etc.
Should NHRA get a Fairplex race in without significantly reduced seating is typically a guaranteed money maker. (Baring multiple days of bad weather.) The population within 60 miles is huge and the 120 mile area beyond 60 miles is also huge. The Fairplex meets all of NHRA's needs and the facility is already there. Its really just about the California government and that reduced seating issue ...and those immigrants. Put em in the beams! (No... not the immigrants.)
Someone can correct me if I'm wrong but I'm pretty sure the race was cancelled due to the corona virus restrictions before the immigrant deal was even done Plus I think the immigrant children are going to be housed in the buildings on the other end of the fairgrounds so I don't see how that would have any affect on the racing anyway.