I had an unconscious purge like the one referred to in your first link - I had my entire CD collection stolen when I was 25 (except it was a lot more than 200 CDs, closer to 600). My first response was to go back and try and buy them back, but I'd lost so many favourites I didn't know where to start (as I couldn't afford to buy that many at the time). So instead I resolved not to buy any of them back and start from scratch. It wasn't a conscious decision to broaden my taste, but I started browsing more widely, reading more widely, listening to the radio more in an attempt to find new music (rather than just defaulting to buying new releases from artists I already liked, as I'd settled into by then), and found to my surprise that my tastes were much wider.

Eventually, after 3 or 4 years (thanks to downloading & having more cash for old CDs) I got most of my old favourites back, but since then my tastes have stayed much broader than they were before the break. I think the problem in my case was that university had ossified my tastes in one specific area, and I needed the break to get back to the broader listening patterns I'd had when I first got into music in my early teens.