The game is coming out in March, maybe?
The Hotline Miami Twitter account just posted this phone number: +1 (786) 519-3708 ext 10.
I called it, like you do, and got a weird message, as expected. “We are 50 Blessings. Together we march … into the future.” Before I could determine whether this was a hint at a possible March (10?) release date for Hotline Miami 2, another voice said, “You have reached a wrong number.”
It took me a few tries to get the number to work again, so keep at it if you’re having trouble.