Women in the Tour de France

So I get the impression that they included women in this stage merely as a marketing exercise, dipping their toe in and checking the response from the audience afterwards?

Yeah. They let the ladies ride alongside after le Tour has already been won, as kind of moving podium girls. Then they can say, "well, we let you take part in the TdF like you wanted us to, wtf else do you want, you hysterical, unreasonable witches?"