They need to have a new race that comes in and almost wipes out the others... Let's say the ahamkara are revealed to have been alive the whole time, but hiding in secret, regaining their strength. In destiny 2, they could come in, almost completely wiping out the fallen(thus creating an alliance with us) and driving the cabal out of the system. I want new enemies. It'd be cool if it focused on the Wyrms and Ahamkara as the main enemies, with vex meddling with their stuff and the fallen being granted some light from the traveler and they are now our new allies. If they don't introduce anything new I'd be disappointed(by new I don't mean retextures enemies *cough* taken)