Hmm, in MySQL land you have utf8, which means utf8mb3, and utf8mb4. Only the latter supports Emoji. It is only in the last releases that utf8mb4 is supported and also the default character set.

I work with WordPress a lot, and up to 3 years ago it was quite common for MySQL setups at shared hosting providers to only support utf8mb3. And Emoji support really did help here to move it forward.