Legal Question in Employment Law in California

You don't give any information on what the "other changes" are. Just changing who your boss would be is certainly not enough for you to quit the new job without reimbursing the costs they advanced for you. There is a California Labor Code provision that makes it both a misdemeanor crime and grounds for a civil lawsuit with double damages to induce a person to relocate for a new job "through or by means of knowingly false representations, whether spoken, written, or advertised in printed form, concerning either: (a) The kind, character, or existence of such work;

(b) The length of time such work will last, or the compensation therefore." The false representations must, however, be material - meaning of such significance that a normal person would consider them to be "deal breakers," i.e., would a person sitting on the jury think "yeah, if I were in your shoes and I had known that change was going to happen before I started work, I never would have taken the job." So it can't just be that you subjectively don't like the changes. They have to be so significant that the person in the jury box would also think they are such a big deal that they wouldn't have taken the job either. The second issue you have is that you will have to prove the employer "knowingly" mislead you about what the job circumstances would be. So if things changed unexpectedly, you are still out of luck.