It would matter when they start the process and ask to fill the actual IM0008 form, where you can specify the current email. Its luck of the draw, file could be sent to Ottawa where you will be saved against the wrath of New Delhi office
If I were you, I would get them here on Super visa or have a 2 year extension from a regular visit visa, then you can legitimately ask for US office in the form as they are allowed to live for more than 1 year. This way, file will 99% move to CPP-O and the process can be done internally ( this is off course if they have retired and live here for extended period )