Yes theres returning rewards.

So after like 15 days of no activity on an account,well i think its 15 days you gain acess to returning rewards which is a stacking thing everyday your off after 15 you get cps,xp so for example i came back to an old account like 6 months no activity think i got around 3-4k cp and a bunch of xp.Also to note returning is stacking also,as in you return collect those rewards then if you go inactive again for over a specific time you can collect again - downside is all this inactivity kills your power ranking.