Ahh then it must be because in SITL we don’t use that parameter, as we don’t really have the concept of GPS instances, and thus it is getting eliminated automatically from the build.
And for hardware targets, yes you would get those parameters, since they are mapped in the board configuration file .px4board, as I briefly mentioned in this post: Confusion on which USART ports are connected to which TELEM ports
Hope that clarifies things!