you are not completely wrong, but you came to the wrong conclusions though:
the story updates always contained 1 full week (start of the week, middle of the week, weekend)
the updates always were made within 1 month (the other month(s) were for DMD game.
Once the paths differed and their number grew in last updates, also because of the possibility to have certain path combinations possible, they had to script a lot more scenes (and also some scenes in multiple ways of outcome) overall to get the full week.
Reasonning this, it should be clear that this additional time has to be "cut off" somewhere which maybe results in slighly shorter scenes. Overall the content per update is neither rushed or shortent - much more the overall-content of the last updates got more. (but i understand that you feel it would be less within last updates, because you probably don't play all possible routes and combos.)
EDIT:
I also may remind on the fact, that MrDots updates content he made within each month EXACTLY on ETA (with 1 exeption which he announced early and delayed for few days - but nevertheless went on point of ETA with next update again).
I dont know any other dev team which is so reliable on holding ETA, giving EXACT ETA each time over 1 month before, and even putting such an ammount of content in monthly updates, where other devs need 3 months (or more) to get less content out