Not all of them, but who would set up a production line for something that will have unknown royalties required to keep it running within the next year or two?

Not all of them, but who would set up a production line for something that will have unknown royalties required to keep it running within the next year or two? It'll take them that long just to get it up and running smoothly. Even if they made zero profit it's a questionable move. "until the WHO declares an end to the COVID-19 emergency or another medicine or vaccine is approved for COVID-19, whichever comes first" could easily be very soon, after which who knows what they'll demand. If they put their patent on GS-441524 in the public domain, on the other hand, it'd be quite clear that they're not creating a situation where the second the WHO changes the status they won't suddenly demand price increases to whatever level they want or punishing royalties to keep producing the drug that the generics company already constructed a manufacturing line for. Maybe an analogy is suitable here -- I see this as like Apple telling everyone that they won't demand royalties on rounded corners for six months. Would you tool up a manufacturing line to make rounded corners if given that proposition? Because setting up a chemical manufacturing line takes even longer than reconfiguring a machining operation.