While your question sounds interesting, and is right up my alley. I am afraid you have not given me enough facts to make a suggestion.
I am assuming you father died, and his will left everything to trust? The Surviving spouse has a will?
Yes it might be a good time for her to update her will, especially if she has designated the decendent as a potential guardian of children in the will, or as the executor, etc.
That said, The will and the Trust are about as connected as the ankle and wrist. While they are both part of the body they have distinctively different functions.
If the surviving spouse has property not in trust, but leaves it to her trust on death, the estate may have to be probated depending on the value.
Likewise, on your father's death, he can only will away what is his, to that end he could will 1/2 the CP to his trust, but the other half would remain that of the surviving spouse as her now separate property.
The upshot is that you should make the investment of consulting with an estate planning attorney. Take all the documents, that are available to you. Note that there could be potential conflicts of interest if the documents create adverse interests between the two surving sons and the surviving spouse. So depending on who you are in this scenario, that may be something to consider when deciding who will accompany you to the attorney's office. If the attorney advises the group on the status of things and gives adminsrative guidance, he or she may not be able to represent any of you in the event anything is litigated down the road.
Your question seems to relate to whether or not your father's will needs to be changed in any way based on his death and the surrounding circumstances (which sounds like everything in the probate estate is to be distributed to the trust (typically referred to as a pour over will)). The answer is that your father's estate and/or trust administration needs to happen now that he has passed away. His intentions and goals that are set forth in his documents will be handled in the administration. If his assets were held (titled) in the name of the revocable trust, then the trust will generally have to be administered on the death of the first person if it is a joint trust. This administration can involve the setting up of subtrusts, notifying the beneficiaries with the required notice under CA law, and other aspects of the administration.
If he held assets in his individual name that in the aggregate were valued over 100,000, then he will have to have a probate to transfer those assets to the trust. If they were held in joint tenancy or some other way where they transferred automatically to a beneficiary, his surviving spouse, or some other way, then those assets will pass outside of the probate process.
If assets were held in the trust, then they will be handled outside of the probate process entirely. If it is a poorly worded trust, then some of the administration may include petitioning the court for instructions on how to administer the trust, but if it is properly drafted then the administration will generally be a private matter instead of public matter and be handled in a much more fast and efficient manner (so long as there is no litigation in the case).
Good luck with your case.
If your father had a trust that was funded, the assets within the trust are not assets subject to probate. Any assets outside the trust that are not will substitutes (Joint ownership and POD accounts) will be subject to probate.
If your mother's will has your father's name in it it does not necessarily need to be "upgraded" or replaced. It may need a codicil or it may not. It just depends on how it was drafted. It would be a good idea for you to hire a local attorney to assist you with the administration of the estate.
Any individual seeking legal advice for their own situation should retain their own legal counsel as this response provides information that is general in nature and not specific to any person's unique situation. Circular 230 Disclaimer - Advice given in this response cannot be used to eliminate penalties with the IRS or any other governmental agency.