It is not strictly "2 per week"
But you get one guaranteed within a set of 4.
So up to this week it was possible to do 20 bosses. That makes 5 sets of 4. Aka you should have had a minimum of 5 Gear drops in total.
But yes, this week the cycle would stard at boss 13, Which starts a new set of 4. If you did all 8 this would make 2 full sets of 4 which should guarantee 2 Drops. So if this was not the case it should either be a bug, or the 95 drops work differently than 75, or it changed as well due to them adjusting 75 drops (which i didnt notice at all).
[Just wanted to make it clear, that originally it was not a flat "2 drops guaranteed per week"]
If that was the case, people would be full geared within 2-3 weeks time at this point.
Can you please explain. 2-3 weeks with 2 drops min (what most people would see) is max 6 items and we wear 15. This is also saying the item that drops is the one you want. I think your math is just a bit off.