It seems like a good replacement but is it functionally the same or better?
Let me point out I'll point out ADuM120N1W is an automotive grade. The ADuM1285 is industrial.
At a high level, the ADuM120N would be part of the latest generation of isolators. The ADuM120N would be the first recommendation for new designs. The ADuM1285 would need to be evaluated in the application circuit to decide if its a suitable replacement.