Google Grants Eligibility & Program Details
You had mentioned in your first post that you had filled out the original form so this should certainly suffice as notification to the grants team. After all, the new policy states, "you may add these to your account at any time without written approval from Google or Google Grants" so notification isn't really required. Myself, I am just a little overly cautious since I manage AdWords grant accounts for my clients and any website that might cross the line of eligibility could result in cancellation of their grant.
As long as the new URL you are promoting follows all of the guidelines for eligibility, is mission based and is CLEARLY tied to (and owned by) your organization you should be good to go.