Well, in 2008, 2009, 2012 and 2013 Bulgaria was not all that hot. No medals at the 2008 Olympics or at the 2008 World Cup Final, no medals at the 2009 and 2013 World Championships, no medals at the 2012 Olympics. This might have been a sad moment for Bulgarians, but the group came back stronger in 2016 after not winning medals in gymnastics in 2008 and 2012. It's important to break traditions because when countries like Bulgaria don't win medals that they were expected to win, they work hard to remain relevant. Look at what happened to Spain: they spent 20 years without an Olympic medal and they finally got one again in 2016. They never quit, never gave up. Italy has also worked hard and this year the routines are much better than they were in the period from 2013 to 2016. No medal in 2016, but I just can't see Italy not winning a medal in 2020.
It's important to break traditions. Other nations joined the top ranks and contributed to a major shift in balance in this sport: Israel has had many big results since 2009, Japan has had huge success since 2015. The world will not stop if smaller nations start winning medals. A good example is the World Cup: when you have countries like Estonia, Switzerland or Brazil winning medals at the World Cup series, this attracts more attention to the sport in these nations. Of course this has only happened once for each of these countries, but the fact that it did happen is amazing, since these are "exotic" nations in a sport that has always been dominated by the same old countries.