Using the average days between each core series Pokémon game I've predicted when the next games will come out.
Release Date In USA Days Till Next Game My Prediction
Gen 1.......................................................9/28/1998...................................748
Gen 2.......................................................10/15/2000.................................919
Gen 3.......................................................3/19/2003...................................1,467
Gen 4.......................................................4/22/2007...................................1,414
Gen 5.......................................................3/6/2011......................................951
Gen 6.......................................................10/12/2013..................................1,133
Gen 7.......................................................11/18/2016..................................1,092
Gen 8.......................................................11/15/2019..........................................................................11/22/2019 (I was really close)
Gen 9...................................................................................................................................................11/22/2022