This is not even a particularly new development. I remember reading a few articles back in 2010 or 2011 where movie studios were complaining that for some film

This is not even a particularly new development. I remember reading a few articles back in 2010 or 2011 where movie studios were complaining that for some films, only the first viewing of the opening night would be sold out. They did some research and discovered that people were pushing social media and twitter updates as they were walking out, recommending everyone to just avoid the damn thing. This was at a time when cinemas would have tickets reserved and you could pick them up from the ticket booth. So what happened, was that people would simply not show up at all and the theatres couldn't even know that there were plenty of unsold tickets until ~1h before the start.