The BSON Symbol type has been "deprecated" for over 11 years https://github.com/mongodb/bsonspec.org/commit/b5b60d6eca910a139a91736922cc04dc30ccdb34 but yet there doesn't seem to be any plan to actually remove it. Removing it would break a lot of client apps esp. in languages like Ruby that support symbols/atoms. For these languages, its quite useful to be able to persist MongoDB data in a way that mirror the application's memory structure.

Moreover it the deprecation "limbo" status seems to be perennial source of confusion/issues, e.g. RUBY-1320, NODE-2518, SWIFT-153

Doesn't the MongoDB team think it might be better to undeprecate Symbol and instead make some guidelines about how it can be used in both languages like Ruby which have a symbol type, and languages like Javascript which do not?