In terms of owning copyright of AI output, there's no definitive answer. But, let's discuss anyways, since I'm assuming you wanted more than "I don't know."
First let's set the baseline. Thanks to the Infopaq decision, we know that the standard for copyrightability is an "author's own intellectual creation" and that this is uniform throughout the EU. Additionally, the author must make "free and creative choices." For more info, see this blog post by Eleonora Rosati who greatly expands on this. Also for more France-specific commentary see here and here (French links).
There's really only two possible ways to assign copyright. And at least in the EU, there's been no definitive answers.
Does the AI output reflect the free and creative choices of the AI author/trainer? Arguments for are that the AI produces only a range of outputs based on creative programming and creatively selected training data. Arguments against are the inherent randomness included in most machine-learning algorithms and that the output of the AI is disconnected enough from the creative choices in original programming and training data. Also arguable is a spectrum - if the AI is simplistic enough that the output is fairly predictable, it could be considered analogous to a tool like graphic design software, thus giving the person who trained the AI copyright.
Is the AI considered an author? This is less likely. It is extremely doubtful the AI itself holds copyright as they aren't legal persons (yet) and can't exercise the rights granted by copyright (yet). As Eleonora Rosati's post pointed out, EU law heavily implies that only humans can be authors. But, what if despite this, the AI is considered to have exercised a "free and creative choice" and would own copyright were it not for lack of human-ness. Then, presumably the copyright could default to the AI author/trainer (sort of a work-for-hire parallel here) or be discarded entirely. Additionally, this might be a point where EU members could differ.
Now off-topic but I'm going to quickly mention UK law since anyone researching this topic will run into it. Copyright, Designs and Patents Act 1988 section 9(3):
In the case of a literary, dramatic, musical or artistic work which is computer-generated, the author shall be taken to be the person by whom the arrangements necessary for the creation of the work are undertaken.
This seems to run counter to all the uncertainty in EU law I pointed out, but in addition to the possibility I pointed out in (2), it could also be held that within the UK these works are protected like copyright, but it has nothing to do with the EU definition of copyright.
But if those possibilities don't pan out (I personally doubt them both) and the EU Court of Justice decides AI output is not copyrightable, then this clause would be null and void (unless they leave the EU before that determination is made...)