Sure, that would also have been a fine solution. There are lots of ways to tackle it really and some of it is just very subjective. There's a lot of similarities here between the NoSQL vs SQL debates. Do you want a schemaless collection of JSON documents or do you want enforced schemas, people can debate this stuff for a long time.

You can also see it as a version control and awareness problem rather than a schema or serialization problem. The issues don't occur if you always have full awareness of what code is running and what's consuming what data, but that's hard especially when you take into account batch jobs.