Please bring back the initial 3 sets.

kliklis

Mewtwo, Pikachu and Charizard boosters must remain!!

TheJeffers

They're not gone. The interface is just a little counterintuitive.

If you touch the button on the bottom right of the screen when viewing a pack, you can select other expansions, including Genetic Apex.

Just because they are not on the homescreen, it doesn't mean they aren't available.