In Maxscale 2.4 support for slaves replicating off of Galera nodes was added to Galera Monitor.

But at least from available documentation its not clear if galeramon can redirect slaves to other active node upon failure of the node they were replicating from.
In MariaDB Monitor we get several replication related variables to do that. But it seems for galeramon they are not present.

This feature will be really helpful to maintain the read slaves of the galera nodes. Thus making 'read-scaleout' feature more robust.