Gaining control of the downlink station is pretty bad. I wouldn't say they were in control of the satellites though. The tasking files for satellites are unique and extremely esoteric, and although it's possible for an attacker to figure out how to command any given satellite (it's not the same for every one), it's much more likely that they compromised the location to get the data that was downlinked, which is extremely valuable. Lots of military instruments downlink through Svalbard and that they might have had command and control over two particular satellites is not nearly as concerning as them having data access to many more in real time.