Regan wants us to think it does not include people who died with, or after, the disease. There is no evidence for his guess.
Wrong Johnny, it's not a guess but a logical conclusion. Spanish Flu affected mainly younger people. Younger people are more likely to be healthier than older people and have fewer or no co-morbidities. Logic would indicate that these younger victims of Spanish Flu actually succumbed to Spanish Flu alone.
Covid deaths are heavily weighted towards older and infirm people. So Covid is more likely to be one of a number of co-morbidities that they suffer from but by no means the co-morbidity that killed them.
Logic, Johnny. You may like to try it some time.