Honestly, I can believe that Charles, Anne and Edward have had a sort of private "meeting of the minds" with regard to Andrew. They are his siblings. I see it this way - Andrew lacks the self-awareness necessary to be anything other than an arrogant, pompous ass. He has for years and I'd bet his siblings are most keenly aware of this. Charles, for years now, has been said to advocate for a slimmed down monarchy. Clearly, Anne & Edward are in agreement with that vision, and have been for at least the last quarter century. Anne and Mark Phillips eschewed titles for their children and raised them to be self-sufficient. Edward and Sophie chose for their children to be titled not as Princess & Prince, which is their right as grandchildren of the monarch in the male line, but instead as children of an Earl. Andrew has, in part because of when he got married and had children, envisioned a far more prominent role for his daughters, even as it became clear in the last 15 years that this was not the direction in which the public wanted the BRF to go.
He just doesn't "get it", refuses to "get it", and is doing everything within his power, behind the scenes, to at least get back to where he was 2 years ago as a working royal. It wouldn't surprise me one bit if, knowing that Charles and William aren't budging and that Mummy is letting Charles & William make these type of personnel decisions now, he's been trying to lobby his way back through his sister and younger brother. Family dynamics being what they are, we all know that Anne and Charles are close, and we know that Edward & Sophie are close to William & Kate. I can very easily see a scenario where Anne casually mentions to Charles just how obtuse Andrew is being while Edward mentions something similar to William, or possibly Anne, and the three siblings have a little powwow where they all agree that 1) their brother, Andrew, is an idiot to think that the public will ever want him back doing royal duties, 2) they (Anne & Edward) fully support whatever decisions Charles & William make for the future of the monarchy.
The fact that this seems to be coming public now, just as Scotland Yard & the Met Police announce that they've looked into the Virginia Roberts charges once more and have nothing that they can or will charge Andrew with and that the matter is completely closed, leads me to think that, once again, Andrew has been making noises behind the scenes to Anne & Edward, asking them to intervene on his behalf with Charles. The anonymous palace sourcing is his siblings (all three of them) way of telling him, as bluntly as they can, since he still refuses to "get it" that they have been in agreement for some time on the matter and it is settled - Andrew will not return to public royal duties. Ever. It's very clear, united messaging. Maybe Andrew will finally comprehend and grasp the enormity of his actions and behavior, though I rather think leopard might change its spots sooner.