Beyond Javacord
Since day one, ClaireBot 3 has been based on Javacord due to it being the easiest Java-based Discord API wrapper to work with. As far as I am concerned, that remains true today. On top of that, it has great documentation and a lovely community.
Despite how much I like Javacord, I recognize one major issue with it: it's development has come to a complete standstill.
This leaves me with two realistic options:
Contribute to Javacord and work to bring it up to date.
Migrate to a different API wrapper (JDA, Discord4J, etc.)
Option #1: Contributing to Javacord
In an ideal world, this is the path I'd choose, however, Javacord is quite out of date at this point, and I'd rather put that effort into improving ClaireBot or working on one of my various other hobbies... which I have too many of.
Javacord is currently using the latest Discord API version (v10, see: Javacord.java and Discord Develpoer Portal), sooooo it wouldn't be completely out of the realm of reason to implement new features.
Option #2:
From a quick glance, Discord4J seems like the best option if ClaireBot were to switch libraries. It uses Spring's Mono classes which can be converted to CompletableFuture. This would hopefully eliminate the need to do major rewrites to large parts of ClaireBot as structure could remain quite similar.