Types in Dgraph isn’t all that “strict”. Types are basically a kind of “convention” and used to “reveal” the format of the node. So, you can even add “hidden” edges that only who queries knows it. What I mean is that, there’s no implications changing the schema over time.
Only GraphQL you are obligated to do things.
You mean upsert bulk update right? there’s no correlation there. Bulk update is a good way to update a database that changes over time.