Their imagined future resurgence scenario -- someone in a lab gets infected, then travels abroad -- highlights one of the reasons developed countries need to help less developed countries: Out of enlightened self interest, not "charity" nor "the goodness of their hearts."
We currently are de facto breeding antibiotic resistant infections in places without adequate sanitation or water infrastructure and you can go from pretty much anywhere on the planet to pretty much anywhere else these days in 24 hours or less. When people from developed countries get sick while someplace else, they are often medevaced out to get them good care in a modern facility, thereby potentially exposing people in their country to whatever they have.
We need to do a better job of providing basics like adequate water infrastructure worldwide if we want to be free from such diseases in our cushy developed countries.
If only we had some sort of massive example that had killed literally a million Americans. Then maybe we'd learn.
Oh well. Maybe when that happens.
And as the other poster correctly guesses, this was a sarcastic reference to covid.