Let's see, the PS4 has been on the market for 3.5 years now, almost 4. Sold 65 million units so far. There could possibly be a PS5 in a year or 3. Hard to tell. If PS4 can keep that momentum of selling 15 million units a year from now it could definitely happen. However, it would be a definite outlier compared to the other 5 systems that have managed to break 100 million (PS1, PS2, Wii, DS, GB).