That is a common social norm, as bizarre as it seems.  I can remember something similar around 2018, it was days, not weeks, but I really had no idea she was expecting me to text her in the days before the planned date.  Like good morning. And hows your day. 
I don't know you, I don't care about your day, we have never even gone out! 
There's also an element of signaling value, with your lack of availibility  High value = low availability.  I think it's really the opposite, powerful people make their own schedules, but that's another convo.  Around 2017, I remember a text convo with someone I met, and she listed her like entire schedule for the week to me, while we were planning a date.  And I said something like next week is cool too, and she was like no I can make Thursday, and then named like 5 more plans that week. Well I have yoga Thursday, networking Friday, birthday on Sunday, self care on Monday, girls night on Tuesday.....