I think the potential of these chips for genocide in the hands of a tyrant is horrifying.
I think the pipe dream of switching women's fertility on and off like turning a switch is just plain never going to come true. The reproductive system is simply too complex.
We already have long-term hormonal contraceptives - injections and implants - but they don't always work to prevent pregnancy, and their collateral effects are not negligible (to any decent person). In spite of the claim that they are "reversible," all forms of hormonal contraception result in an higher incidence of infertility, either temporary or permanent.
In order to guarantee sterility absolutely, the drug would have to be so powerful that it would either quickly persuade the women to "turn it off" or it would make them so sick they'd do a poor job as sex partners.
It sounds to me like this is basically a 16-year supply of "the pill" inserted into the woman's body, and then released in doses via wireless signal to an implanted microchip. I don't know how the chip would know where a woman would be in her cycle, but I'm sure the fine engineers at MIT do.
This could really escalate the population implosion, particularly in the West.