Here is what our Product teams has replied:
"Regarding the query, it is quite high level – so although it looks a “good approach”, there are still a lot of design decisions that the customer could take that could rapidly turn it into a “bad approach” 😊
That said, at a high level, it seems customer has decided that data structure fits well with a document oriented database, and seems to have identified a pretty good use case for Change Feed."
Here we will advise you to create POC and check the use case is working for you before you move to doing the same for production.
Thanks
Navtej S