If you possibly can, see the French movie that inspired this

Well, I think that we would need some evidence that The Beatles had ever even heard of the film before accepting any influence.
The reason that the film isn't available is almost certainly that it is thoroughly obscure. You could be interested in film, including French films for decades without having even heard of it. Many films, many much more famous and marketable, aren't available for all sorts of rights problems.
The Beatles were never slow to credit influences, even on their biggest hits, I'm not sure why they would bother to suppress evidence of influence on one of their least successful or visible endeavors.
As has been mentioned elsewhere, Magical Mystery Tours were a very common phenomenon in the UK at the time so if that's the only real similarity then it's a bit like saying that if there are two films set in a fairground then one of them had to be ripping off the other.