It isn’t a speculation it’s confirmed that Sony has some new products and they believe 23 April as a sweet time to launch. From the another side it’s also included that no E-mount camera or lens announcement on that very day.
Let’s see what are the two things that Sony is in a full pace to launch these.
1) New RX cameras. Very likely the RX2 with curved sensor and 35mm f/1.8 Zeiss. Or a new RX10 successor.
2) New A-mount camera- A99II or a new A58II has a good chance.