This article explains how to get the system updates - Particle Dev is not one of the supported methods at present. Particle Firmware Updates Thread
Sorry it’s like this and that we even need this kind of list of exceptions - our offering is a bit fragmented in places regarding how system firmware updates work and what compiler versions are used. I’m asking internally to get both CLI and Dev on feature parity with the Web IDE regarding version selection and updating system firmware as part of compile. The back-end services are also being radically overhauled to fix this problem so that the device is given the system firmware update when it is needed, no matter how the new application firmware came to be flashed.