GEN I: February 1996 - November 1999 (3 years)
GEN II: November 1999 - November 2002 (3 years)
GEN III: November 2002 - September 2006 (4 years)
GEN IV: September 2006 - September 2010 (4 years)
GEN V: September 2010 - October 2013 (3 Years)
GEN VI: October 2013 - November 2016 ( 3 years)
GEN VII: November 2016 - December 2018 (2 years)

4chan: ARE YOU CRAZY? WHY WOULD GEN VII stay 2 years???

Me: Honestly, i think nintendo would want a new pokemon game for the switch and it's pretty obvious that the'll want a new generation with it, i aalso don't see why GEN VII would last longer, it doesn't really need to.
Though, this means GEN VIII getting 69 pokemon at most.