I am in same situation (have appointment on 8th July in Dehli) and had emailed US travel docs, I got below reply:
Thank you for writing to the U.S. Visa Service Desk.
We understand that you have a query regarding the appointments.
In response to your question, We would like to inform you that any update regarding the scheduling changes on US visa appointments. please follow our website: www.ustraveldocs.com/in if there any update of the cancellation in the appointments you will be notified through the email from the US embassy/Consulate. Please proceed with your scheduled appointment.
You should arrive at exactly the time of your appointment; there is no provision to wait in and around the Embassy/Consulate area. Kindly follow the link Apply for a U.S. Visa | Attend your interview for information regarding Security Regulations.
We hope this information is helpful to you.