Troubling indeed. For me that's a prime reason I don't want Android. But for those less fortuned (either mentally and/or financially) it might do the trick, resulting in a larger ecosystem.

Perhaps they use the "Nexus scheme". Google releases open, pure-Android variants more or less under its own brand name as "Nexus devices". However, other companies are still free to lock up and crap up their Android devices trying to differentiate themselves. So, Jolla might release a clean, open, high-end device which can act as showcase. But other companies can create their own variants, perhaps with extra (closed source) features developed and supported by Jolla, such as this advertising-stuff.

Another way to make money, as used by Google: Android, the OS and base applications, is free and open, but those common Google-tools as Google Maps, Play store, GMail are not open and certainly not free for other manufactures.