In CA, is the employer required to notify it's employee of the expected date of return to work when out on a FMLA leave so as not to jeopardize continued employment?

Employers are required to give a brief explanation of the benefits of FMLA. A sample notice may be found at: http://www.dol.gov/esa/forms/whd/WH-381.pdf
The statute describing FMLA notice requirements may be found at: http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_825/29CFR825.301.htm

A comparison between the California leave law and the federal leave act may be found at: http://www.dol.gov/esa/programs/whd/state/fmla/ca.htm

So, in answer to your question, qualified employers are required to inform employees of their benefits under FMLA, both at the federal and at the California level. However, a specific date is not necessary.

Also keep in mind that if you are on FMLA leave, the company does not have to hold your exact job open, but must provide something similar upon your return.