Ok, read their actual pitch. Lmao they think that a one time introduction of a GMO bacteria strain is going to 'just work' because they've also GMO'd it to outcompete other bacteria?

There's a reason we aren't running our cars on yeast-produced gasoline. No matter how awesome your tuned microbe is, it's still subject to mutation and natural selection. If your beneficial changes aren't actually helping it survive, they will not be conserved. And those 'competitive' changes you jacked it up with to make sure it dominates the environment? Well, that might end up horizontally transferred into something you don't like.

About the right amount of 'we humans are smarter than dumb biology' metal-fetishism I'd expect from the folks concerned.