It is just too early to say how successful this program will be so we just need to wait and see.  The fact that the women are there voluntarily and can leave if this is what they decide, I really do not see a problem.
It is very similar to the Federal Witness Protection Program  which has operated since the mid 1960's  by the Dept of Justice and the US Marshals Service.
Defense attorneys can claim that the program operated by Prosecutor Kaneshiro is unfair to their clients but  I suspect that the Courts will not agree.