Cynical summary, basically: "The first patent on GS-441524 was issued in 2009, while the first patent for remdesivir was issued in 2017."
At least assuming people get vaccinated.
"On 12 May 2020, Gilead announced that it had granted non-exclusive voluntary licenses to five generic drug companies to manufacture remdesivir for distribution to 127 countries. The agreements were structured so that the licensees can set their own prices and will not have to pay royalties to Gilead until the WHO declares an end to the COVID-19 emergency or another medicine or vaccine is approved for COVID-19, whichever comes first"
https://www.gilead.com/stories/articles/an-update-on-covid-1...
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.
Also, sure it was patented earlier than remdesivir, but patent term is 20 years - GS-441524 has 9 more years on patent. Plenty of exclusive value that Gilead can extract.