This does the trick. I create a new custom list view inherited from the old one and override reload_content():

[...]
    instance.web.views.add('custom_list', 'instance.web.CustomListView');
    instance.web.CustomListView = instance.web.ListView.extend({

        reload_content: function () {
            var self = this;
            this.conf_model = new instance.web.Model('customer_stats.config');
            this._super.apply(this, arguments);
            custom.whatever();    //this will get called everytime the list is loaded, reloaded or changed
       }
[...]

In the "my_view.xml" action section (ir.action.act.window) custom_list needs to be used instead of list or tree.

[...]<field name="view_mode">custom_list, form,kanban,graph</field>[...]