Taking the 5th division out of every league was a mistake
Adding iron and grandmaster tiers was honestly a good idea. The ranked pyramid was getting a bit cramped.
Ripping out the 5th division from every league was not, and it was especially not a good idea to push everyone in said 5th divisions straight to the 4th divisions. All that space that was just added means nothing due to this, and in fact it's made the entire ranked pyramid a mess.
Pre-season and the beginning of each ranked season ranked will always be a mess due to how it's designed but removing the 5th division mattered so much. With leagues being smaller(aside from the top tier) and the forth 4th division being cramped, it's no wonder you have people dropping to ridiculous ranks.