The length of time that you have resided in the home is of no consequence with respect to your rights to continue the occupancy. That is unless you have a contractual right to do so.
The decision as to whether you will be allowed to remain pending the probate process will rest with the personal representative who is vested with the sole management and control of the property of the estate. And who must in good faith “exercise ordinary care and diligence in managing the estate as determined by all the circumstances of the particular estate.” (California Probate Code Section.9600)
I’m sure the language of the California statute is confusing, but what it means is that the PR’s prime responsibility is to protect the interests of the creditors of the estate and the beneficiaries under the will.
So if the PR decides that serving those interests require that you vacate, then so be it.