I mean, in a way I get not divulging any files until you're absolutely sure.
But I doubt a company is gonna go further than an official saying "We have decided to cancel the project 'Kingdom Hearts: Missing-Link' since we couldn't find a way to properly make it for the fans."
I'm sorry, but the announcement seemed pretty cut and dry. And since Square ain't the type of company to just accidentally post or put out a huge statement like this on a whim. We can all assess that the game is dead... for now. Maybe it'll get made into a special-film like Union Cross or a DLC for Kingdom Hearts 4. But the game project for Missing-Link is dead.
Of course, if you guys wanna take your time to confirm it. Then by all means, do so. I can wait.