So out of curiousity I emailed FW about the Guard stuff and they sent me a reply:
So FAQ inbound in the somewhat near future.Hi there.
Our rules team will be reviewing the effect of the Astra Militarum Codex on our self contained Imperial Guard based army lists such as the Armoured Battle Group and the Elysians. Once this review is complete they will make the necessary changes (if any) that are needed in an errata.
If there is anything further we can do to assist you, or if you have any queries about the information we have requested or provided, please telephone us.