So, I noticed this in the last yearly review:
Since I often use Windows built-in emoji selector, I thought the first link, which is a topic I made, showed the emoji as it used the Unicode emoji character. But if I copy-paste the table here:
:speech_balloon: is properly displayed.
My guess is that this is a slight issue with the plugin itself when handling emoji short codes, while Unicode emojis work out-of-the-box in this context, but I could be wrong.