OK. Thank you for providing that missing information....There are both through-hole and SMD options for the JFETs. The 'empty rectangles' with the label right next to them are for the SMD part. Only one should be populated. This makes the project more viable for more people since (real) through-hole JFETs are harder to come by.
Also, as @PedalPCB said, it's quite rare that the silkscreen for those pads is missing.