Perhaps this could be handled by this functionality:
https://mariadb.com/kb/en/mariadb-maxscale-24-mariadb-maxscale-configuration-guide/#events

So the basic principle is that you can define the syslog facility and level that should be used when certain events are logged. If you use another facility than the one used by default, you will be able to easily pick these out from the syslog message stream.

The underlying mechanism is generic, so if you can clearly define a particular event, it's possible to add support for it.

Using the streaming log API that already exists in MaxScale to implement it elsewhere should be pretty easy. Since it's a WebSocket, a simple Node.JS script could work:

const ws = require("ws");

const sock = new ws.WebSocket("ws://localhost:8989/v1/maxscale/logs/stream", {auth: "admin:mariadb"});

sock.on('message', function message(data) {

    /* Add your logic here to determine what to do with the log message */

    let js = JSON.parse(data);

    console.log(js);

});