Doubt it's any of those to be honest.
Benteke always had the £32.5m release clause, so Delph will have known Villa had no control over him staying.
Delph already had the £8m release clause, and he'd already agreed to the terms of his City contract, so it wasn't those that were an issue.
Delph and Pogba are 2 entirely unrelated transfers, there's no way one becomes more, or less, needed/likely based upon progress, or lack thereof, in the other deal. As to appearances, I can't imagine that will have changed. He won't be guaranteed anything above what he had already been told.
However, as to why there's been a second 180 degree shift in this deal in a week is certainly baffling.