I believe standard co-founder agreements have a "without cause" termination or "resign for Good Reason" agreement which accelerates the co-founder's vesting cyc

I believe standard co-founder agreements have a "without cause" termination or "resign for Good Reason" agreement which accelerates the co-founder's vesting cycle in event of death or disability. The transfer of shares by will or intestacy to immediate family members may or may not be subject to a repurchase option by the Company. Tl;dr it depends entirely on the specific wordings of stock purchase the agreement.