Won't happen. Pre-features, like pre-movie ads, are not there for the benefit of the viewer.

I dont understand. for who's benefit is an interview with director about the film you are about to watch screened.

I think the interview is filmed primarily for the ability to say it exists on marketing copy, thus hopefully sell more tickets. It offer something "new" that differentiates the cinema screening of an old movie from any of the alternative (legal or otherwise) ways of viewing it.

The interview itself? Probably doesn't matter. But for the people involved, it would suck to see no one viewing it.

I'd expect there would be plenty of people who would choose to view it. For "Alien" I'd expect a big chunk of the audience would be people who have only seen it on home media but became huge fans and have watched it many times. They would know every scene, so nothing in the pre-movie extras would be a spoiler for them.

That doesn't make sense. If that interview sold a single ticket more then you already have people who obviously wanted to see it

Not necessarily. People often make purchase decisions based on overall feeling, versus specific, discrete benefits - they'll choose a "fuller experience" because it feels more complete, and then end up not bothering to go beyond the "basic package".

And if nobody goes to see the interview, that’s an important signal to not waste time on doing them.