Bad enough that you force me to update a working piece of software.
Having it clear all my downloaded tracks, as well as reset all the 'Download' flags for the desktop app, is really pretty crappy. I had a specific set of songs setup, now I need to spend my time and my bandwidth to re-download gigabytes of data.
Consider me a not-really-happy-with-your-work premium user. I hope your developers and product owners put some time into thinking about how your product is used outside the demands of your short release cycles.