From the article:
When we went to our seats, the wait staff let us know that despite the fact that the previews were playing, we wouldn’t know until the movie actually started whether we could see the film or not. If it didn’t work, the screen would just turn black. Luckily, the film went through without a hitch.
Ah, so “Company provided service, but then ditched it and now theatres are left to buy more expensive (and likely locked down) hardware in hopes the next company doesn’t pull the rug on them again”