I'm putting this out there and saying that if you seriously believe that Gen VIII is next year, you are legitimately dumb. Before we get into "muh patterns", let me describe how a new generation is made. Basically, it begins development as soon as the prior generation is released.

For example, Gold and Silver began development in early/mid 1996 and came out in November 1999. Ruby and Sapphire began development in late 1999/early 2000 and came out in November 2002. Diamond and Pearl began development in late 2002/early 2003 and came out in September 2006. Black and White began development in late 2006 and came out in September 2010. X and Y began development in late 2010 and came out in October 2013. Sun and Moon began development in late 2013 and came out in November 2016. Sun and Moon didn't start development right after ORAS came out (though going by interviews, ORAS might have started development near the time X and Y were released, which explains a lot). Game Freak has different teams working on different games, and Masuda's team typically handles the start of new generations.

"Began development" does not mean "began programming". It means began researching locations, visiting those locations, looking into current hardware and what can be done with it, coming up with how long you want the development cycle for this game to be, deciding the themes you want to explore, investigating how suitable your current engine is for what you want to do, etc. Hundreds of designs must be made, not only for Pokémon, but for characters, buildings, story events, moves, anything that has a visual to it. The amount of work that goes into a new generation is not something that can be accomplished in 2 years.