Same as with some of the plugins with native libraries, Spark is not updating emoticons packs that were already extracted in the user's profile after you upgrade Spark version. Newer packs are extracted only if you delete old ones in your profile (xtra\emoticons). So any updates to current packs won't propagate to old users.
At least known on Windows
Tried to add a comment to POPO emoticons plist file. After the upgrade this file hasn't changed in user's profile after running Spark. But it has updated in the installation folder. But Spark is not checking for updated emoticons packs and do not extract them again.