Hive.Blog is not Hive. Hive.Blog is just a frontend (website) allowing you to access content stored in the Hive blockchain. The Hive blockchain itself is a speech free platform. You cannot hide/remove content from the blockchain, Hive.Blog is only preventing it from being displayed on its frontend.

Using a block explorer, you can access and view any hidden posts or comment, your hidden comment for example can be viewed here:

• https://hive.ausbit.dev/hive-139531/@introvertspeaks/re-quochuy-r07lgu
• https://hiveblocks.com/hive-139531/@introvertspeaks/re-quochuy-r07lgu (Hiveblocks is down currently)

If you are a developer or know a developer, you could even create your own frontend that does not hide anything.

So while you could say some Hive frontends are not fully free speech, Hive itself is.