I think ESPN Club is a better fit at BW than AC...AC at AKL does make sense. I have no idea where it would go, though...Boma and Jiko I think are too popular to remove. But I think it is a great fit, giving the AKL a "destination" status even for non-resort guests.
I'd caution that this rumor may be a corruption of the "AC at AK" rumor of old, where the AC was to be a gateway into Nightly Kingdom/Jungle Trek, which also has vaporized. We've heard so many different things now, and timelines come and gone, that pretty much anything short of an actual press release from Disney has a very low confidence factor - and even a press release would be pretty low until I could actually TOUCH the location.
As for AC's moneymaking potential, there was a report that AC did make a very modest profit towards the end...I don't know if that was pre- or post-closing announcement, or how close towards closing it was, as there was probably a boost from the announcement in attendance. It was not necessarily a profit that would warrant it staying open (obviously).