They either removed it, or revamped it so heavily that it is no longer applicable to your complaints and no longer suitably described by the term Divergence. Either way you're splitting hairs here. Ethics divergence used to operate either by shifting your population either towards your empire ethos, or away in a random direction, thus the use of the term divergence. Your strategy was 'mind control lazers' 'unity temples' and 're-education plants.' In the long term, you converted deviant populations to your own ethos and you stopped having problems with them. You still seem to think this is how it will operate despite presumably having read the explanation that it no longer will operate that way.
As of Utopia what happens is that your populations will shift ethos to reach a mean close to the attractiveness stats that you can see on the page I linked. This mean is reached by a combination of local affects AND empire wide affects and populations affected by these local affects will also have a higher percentage chance of being the ones that shift into that ethos to bring you up to the mean. Mind control lazers may still be a thing, but if they do anything, it's going to be a bonus to the attractiveness of your empire's ethos, it won't be flipping the switch on some populations so that their ethos shift towards you instead of randomly away from you.