Ok alosso if you think found the only reported case, and I should have said case before, then fine.
This person doesn't have significant earnings or a long and great MP record, in short there isn't an obvious reason they should have been promoted where many others were not.
I'm sure you also know that not all rounds show instantly in the score history and, whatever did show, he had played as that was neccesary for the promotion (I know, maybe quit etc). Perhaps speak to them and ask after what the upgrade came?
For the vast majority what was needed was to be saturated, average under 55 and to play.
I'd say there is a strong possibility wgt will change the number of rr's to saturate in the future, less likely the average. They had to put it at 200 for now as they seem to have wanted their new tier populated.