Basically, a LOT of people go into their Bo5 and went 2-0 in their series. So now they're going to sit on their 2-0 until the last week of the season to finish their series and hopefully win their way into Challenger. As a stipulation, you have a 1 week safety period when you get into Challenger. This means that at the very last minute they're going to throw someone out of Challenger and lock their spot in indefinitely so when the season ends they're guaranteed to finish Challenger.
I really think they should limit the amount of time you can sit in a series, maybe to a few days. Make it so that you HAVE to play at least ONE series game every 2-3 days so that you're not afk'ing in the series for 1-2 weeks at a time.