No new film scores on the horizon, it seems
Spielberg's latest film is an adaption of a Leonard Bernstein musical, so likely no Williams involvement there. Spielberg's next scheduled film after that is supposed to be The Kidnapping of Edgardo Mortara, which is listed as in "pre-production", which health permitting Williams would likely score. However, with COVID-19 who knows when this film will actually be completed. The next Indiana Jones movie is supposed to be start filming soon - but again with COVID who knows? In any case, now that Spielberg has dropped out Williams might not do it anyway. There will be another Disney Star Wars film in the pipeline, but I doubt Williams will do one not involving the "legacy characters". And, of course, the elephant in the room - his age. By the time any of these projects would be ready he'd likely be near 90.