Well, if the NPC market has nothing to do with it and it's a power generator's owner, then that's their call and that's fine. That'd be nothing new. It is just that the timing between being listed as powered, then made over and shown as no longer powered, was so tight (hours) that it seemed (and kind of still seems) unlikely to me that someone, without getting any events about the change of ownership, could hop from city to city to unpower facilities so quickly. If the owner(s) of the power generators wanted to buy those facilities themselves and not power them for someone else, the smarter thing would've been to depower all the facilities ahead of time, to discourage people from bidding against them. All other facilities on the same planet are still powered, though.
But maybe it's possible. Do city owners get notifications of sales and can power be managed remotely now? (That's the only thing I can think of that might explain the timing. Apart from coincidence...)
And the CPM mention was a force of habit typo. Sorry. I know the difference. It's just my fingers that don't. -.-
In the meanwhile I guess I'll just have to wait for portable power gens to be implemented.