<...>It's also noticeable that more and more Junior Members that have 1 merit after that day.
Before that day, I believe that it is hard to find a Junior Member with at least 1 merit.<...>
There were quite a few before the change of rules (just over 5K):
As of 21/09/2018: 6.561 Jr. Members with at least 1 received sMerit (after the change of rules).
As of 14/09/2018: 5.087 Jr. Members with at least 1 received sMerit (before the change of rules).
As of 07/09/2018: 4.908 Jr. Members with at least 1 received sMerit.
You can see the boost caused by the change of rules though, going from a weekly increment of just 200 cases the week before, to nearly 1.500 after the first four days of change in rules. Most are re-ranked cases (1.463 of them back to Jr. Member from Newbie). Aside from that 145 Newbies that did-not rank-up were merited for the first time, and 29 went all the way up to Member from Newbie.