Have heard nothing about John Williams or the LSO's return to Indiana Jones but it is still early at this point.
At least Steven Spielberg is directing it, early on there was some indication he might not and old georgie would direct it himself.
having Kathleen Kennedy who worked on e.t. as the producer is also a very good idea. as well as it being shot on film, any dumbass who considers himself a cinematorapher knows HD video does not reach the quality of 35mm motion picture film and is not a lasting format for archiving for the future.