Does ServerTravel discard any maps being preloaded on client machines?

Hello, for our game we have the ServerTravel be called(with seamless travel enabled) and the client’s will transition to their new map but we wanted to see if we could preload the new map using stream handles(that the Game Instance holds ontu) and wanted to know if ServerTravel gets called before the client’s finish preloading the map(so its currently async loading but not done loading), will that information that was preloaded be discarded for the blocking load or will it be changed from async to blocking?