Not sure at all about the Cambridge 101 office. Seems like anyone from the last round of promotions is in the 'safe' list as well as those outside of XA/XD.
Almost everyone else received an email telling them that 'Under the current proposal, your role is identified as being in a pool which is provisionally at risk of being reduced in size' . Not sure how legal this phrase is considering that some of the last batch of promoted are in the same 'role' as me and have received the 'safe' email.