If you know a bit about bowling machines, you'd know how impossible a task this would be. These machines are huge, highly complex and take up A LOT of space. Not to mention that they are noisy and expensive to run. Even so, they fail pretty regularly, must be serviced by trained personell.
Problem 1. Ideally, the balls would come down from above. Somehow the "ballsetter" must be integrated into the lighting, or move the lighting aside when setting the balls down. The balls must therefore be transported up to a height above the lights. Would need a long tube, and only work if the table was close to a wall, otherwise the tube would be in the way. You could of course manually load the "ballsetter" but then, what would be the point? You'd need a very stable frame of some kind to hold heavy machinery safely above the heads of people playing. Even so, I'd hate to be the one responsible when some guy gets a 20 pound or more piece of metal in head from 6 feet above....
Ok, maybe the balls could come in from the side or the rail behind the racking area. Then you'd need very wide rails, that somehow open to let the triangle in onto the playing surface. Maybe the triangle would come from below and "flip" inside or something. Needless to say, it would be difficult to do, and lead to unsatisfactory table performance, not to mention that the cloth would be worn out, if the rack had to touch it.
A robotic "arm" spotting the balls would probably be the most practical solution. It could fold away when not used. It would be EXTREMELY expensive and complex. And would probably develop problems as the balls got worn, as well as the cloth.
Problem 2: Cost (electricity, maintainance, parts, the machine itself, extra requirements for the building itself). You want to play pool? That'll be 50 bucks an hour.
Problem 3: Safety. Moving parts near pool players and drunks. Nah, probably not going to be a problem
I just don't see any way, that either of these designs could be operated in a way that authorities would deem safe. You'd probably have to wear a hardhat and steel toed shoes to be allowed anywhere near them.
Problem 4: Racking performance. As we all know, racking tightly is very difficult to do, since the racking area develops wear, as does the balls. A machine would have to operate a bit like the Sardo rack, pressing the balls down, to have any chance of success. This in turn, increases cloth wear and eventually will make even the machine fail.