You're right and usually Led by Donkeys forget this, too, which is why they're not funny! But maybe this is a sign that they're about to turn over a new leaf and become actually amusing.
They are annoying because they're just grifters. They claim to be speaking "truth to power" but really they just make shit jokes.
Of course they're going to say that Labour is fair game now, because how else are they going to get money from people just from following Liz Truss around?