At 1.5% ownership, YC has no say over the direction of the company (other than through the influence they have from being well-known and respected in the startup space). The conflict arises when your VCs sit on, or even control, your board. Then you, as the Founder/CEO, can be forced by your board in directions that you don't want to go. That situation simply does not exist here, with YC taking such a low ownership stake. Nor does it exist in the normal YC program, since again, they do not take board seats with their 7% stake.