This already happens without GMOs, e.g. Africanized bees. Meanwhile, having a dead man switch would turn GMO-based food systems into a potential weapon (i.e. don't mess with us or we'll put your country into a famine).
And the bees might be an invasive species, but they have no superpowers. I'm not sure how wide the biological niche of a GMO plant can get.
For the dead man switch: maybe the activator could be something simple and well known, just not so common in normal surface soil. But I don't even know how big this risk is...