We're intentionally getting conflicting information because there's obviously two high-level employee/executive factions still internally fighting over this. One wants in MC, one wants in AC. They are fighting for many different reasons such as costs, having to move office locations, future expansion ideas in the two plots, even wanting to just preserve Muppetvision. If the location was known they would have announced this with the Monsters blog post a few days after D23 like they did with Cars.
News and "leaks" are meant to conflict with each other because each side wants to get over the other. The articles and social media campaign to save MV was very planned and got the backlash they wanted, with connections to influencers and even journalists to set it up up to a month before D23. That response might save MV, but at the very least will ensure Muppets will have some attraction going forward.
I wouldn't be surprised if it still isn't decided, there's no indication it is. Whoever is supporting MV is going to fight for it until the very end too, as I think they have since they first planned it there. So really, we can't know anything about this until it comes from the mouse's mouth. Which can be tomorrow, or months from now, who really knows.