Hey, my exam officer said that even though the government has changed the exam system this doesnt effect retakes. You can actually retake your A2's next year and fail and then retake the next year after that as he said the retakes are open for two years. The reason for this is because previous years had the same opportunity, therefore it's not fair if its taken away from us.
Of course double check this with your exam officer, but I assume this is right.