Pardon the bias, as ~600 Pokemon were cut, but they cut Absol, my baby. Make your own of your favorite if it got cut!

I'm bitterly disappointed that they left out Absol... :(
Houndoom and Lycanroc, too! Those are three of my top 10 favorite Pokémon of all time!

https://www.youtube.com/watch?v=KXSUwUlLRHI
all the Pokemon that didn't make it into Sw/Sh

They may be planning on dlc to slowly bring all the Pokémon back and wanted to make sure that they finish the game on time.

I sure hope you're right...