The Advisory Group was closed last year and replaced by a new Strategic Oversight Board, although the news of this is only contained in the minutes of the final meeting (PDF) chaired by Tim Kelsey, who has since fled the NHS to take up a director's role at the Australian medi-telco Telesta Health.
Interesting note, Telestra Health are now making lots of money out of NHS data, and as Mr Kelsey is a director he can expect a fat bonus.
I wonder if there's a connection between that and all the work he put in while working for the NHS to commercialise NHS data ?
See also https://www.opendemocracy.net/ournhs/tamasin-cave/tim-telstra-and-tech-takeover-of-nhs