The Pan European Game Information Board has rated Ape Escape 2, Dark Cloud 2 (Dark Chronicle), and Twisted Metal: Black for PlayStation 4.
Twisted Metal: Black is already available as a PS2 Classic for PlayStation 3 in Europe. It was released in September 2012.
This would appear to be Sony bringing its selection of PS2 Classics from PlayStation 3 to PlayStation 4. If anything, you might find out for sure tomorrow, as Sony is holding its SCEJA Press Conference 2015 in Japan.