So I had this exact same issue and question. I called ADEA AADSAS (and a bunch of schools I was applying to). They told me that if I know course codes, course titles and credit/unit information, I could enter all that info under "planned/in progress" coursework. Since I wouldn't be attending the school until Fall and have not yet taken any courses pertaining to the Masters, there was of course nothing to send them and this wouldn't hold up my application processing. If, however, you know you'll be doing the Masters but DON'T know the details of the coursework, then they advised against entering this on the application since you'll have no planned/in progress coursework to report... that'll hold up your application since they'll think something's missing or they'll think you forgot to include this info and send the app back to you to re-do and re-submit. Instead they said in this case to mention it in the personal statement and supplementary applications of the schools.
I initially decided against entering the information, but then I decided to call and email the school I'll be doing my Masters at and they sent me all the necessary info (course codes, titles, semester I'll be taking the courses in and credit/unit info) so I could enter this on AADSAS. This won't hold up your application in any way since all the coursework for this school are planned/in progress. ADEA will know when they verify your GPA that there's obviously no transcript 🙂 I submitted and all went smoothly without hold-ups or questions regarding this from any schools that have contacted about supplementary apps nor from ADEA.
When you're entering your coursework, every time you add a new semester/term, it'll ask you whether this is a completed semester or a planned/in progress one. You would select the latter since it's a future date and then fill out the course work appropriately. Don't leave it as is with NG as you stated above because your application may be held up and not processed properly .. they'll wonder how you have a NG credit for a semester you haven't done yet in a program you haven't started yet. They'll send it back to you to fix and this will delay things. If they overlook this, it could impact your GPA calculations and also confuse ADCOMs. So definitely fix this!
Hope that helps and LMK if you have more questions! I was confused about this for a while until I called ADEA and had them clarify all my questions haha
