Upon doing some testing with trying to remove a team suffix from the tablist using setPlayerListName, I discovered that I'm in fact able to setPlayerListName above 16 characters with no issues (server or client). Thus, the javadocs on this method is outdated:

https://hub.spigotmc.org/javadocs/spigot/org/bukkit/entity/Player.html#setPlayerListName(java.lang.String)

If there's a better place to report Javadoc issues please let me know.