Large media companies don't troll like this. Businesses don't make friends by teasing their customers about sequels to popular properties - a good April Fool's joke from an anime studio/distributor is always obvious. It's just a coincidence ACE ran until April 1.
Plus this is a giant anime expo. Why would they use an event with 50,000 attendees just to troll? These are the events where they announce new projects like this.