I would say that the most likely deterrent is the growth of this new market they've found, combined with the knowledge that many vapers test stuff, and would report such a thing faster than one can strike a match.
Nothing is impossible, but the incentive for continued profits has proven to be one of the strongest forces known to mankind.
Again, just my opinion, but we KNOW that the read these threads, so they'd know that vapers are anything but "trusting". See the threads related to diacetyl, and carcinogens, and age-validating software, and-and-and...
Have you considered DIY'ing your juice?