BGOs do not know about appointments before candidates; we usually learn of them about a week after the candidate does. BGOs MAY learn of a potential turndown before it goes out. However, we are not permitted to inform candidates because, occasionally, the status will change before the TWE actually goes out. Nonetheless, some BGOs still inform their candidates, which we aren't supposed to do.
It could well be, in the case of the OP, that the BGO contacted Admissions and requested to be allowed to share the info. I can't speak to that particular situation but, for others out there, PLEASE DO NOT ASK YOUR BGO ABOUT A POTENTIAL TWE. It puts him/her in a very awkward position and will not change the outcome. Not only that, there are many candidates for whom no official decision has been made (I have several of those). So, if those candidates contacted me, I wouldn't have anything to tell them other than to keep waiting.
Finally, as to the question above, there are quite a few potential scenarios. I've sent you a PM.