I don't think this is a completely, totally new thing. I remember reading in my one required college level health class back in 2012 that for serious cases of obesity there were surgeries that involved messing with the intestines or something. I don't remember the exact details, unfortunately. I wonder if this is related to that surgical procedure in any possible way.
And yes it's gross, and people should learn to have more self-discipline, and it could enable people to indulge without consequences, but it could potentially save lives. Don't get me wrong, I'm not endorsing this product, but considering it's arguable that these days, more people in the world die (indirectly) from overeating rather than starvation, well, it's a start I suppose.
That said, there has to be a better way to "deal" with obesity without resorting to mechanically emptying people's stomachs and take away personal responsibility. Maybe something that could help people to learn to deal with cravings, or something. After all, self-control is technically a skill, and sometimes people need temporary "training wheels" when learning a new (or almost never used) skill until they get enough practice in to manage on their own.