Given that the order of the keys is specified as having no significance in regular JSON[1], this is out-of-spec usage.
If key order has to be preserved then a blob type would be a better fit, then you're guaranteed to get back what you wrote.
For example, SQLite says it stores JSON as regular text but MySQL converts it to an internal representation[2], so if you migrate you might be in trouble.
[1]: https://ecma-international.org/publications-and-standards/st...