After speaking to all parties involved (Beneficiaries, Trustee, and Trust CPA):

1. A trust tax return is completed every year. California based. 
2. Taxes are paid by the trust (how the grantor designed it)
3. A 1041 is issued to each beneficiary (they just never had to open the CPA packet so they never seen a form 1041-ES since the trustee handled all the taxes before funds were disbursed)
4. K1 is NOT issued since trust pays the taxes due on the income (unfortunately at higher tax rates). 
5. Final disbursements were handled the same as every other disbursement over the last X years (trust calculates taxes due and will be paid lump sum via voucher for 2025)