I reported similar feedback, along with the basic needs of content managers, here: https://forum.asana.com/t/real-date-shifting-still-urgently-needed/
My jerry-rig was to create a Google Sheet with [=workday(date,-days needed)] used throughout to spit out the dates, plus a cute visual timeline with the Bubble Chart according to this tutorial: How to Make a Timeline in Google Docs and Google Sheets + Free Templates
I then manually copy each of these dates into Asana, preferably over a Scotch