Congrats on dodging a bullet and sorry for the closure.
If you really like a card but really don't need or want to use it often, take it out for a spin every couple of months to ensure it gets enough usage.
Cards aren't nearly the work of having to walk a dog every day, but they do require some attention to keep them alive, something along the lines of a cactus.
Sorry to hear about Chase card closure. We are in the middle or economic downturn and every bank is tightening their accounts. I am sure things will pick up soon and you might be able to get a new card with Chase.
Sorry about the closure but congrats on Chase being upstanding and not bagging you with fees and damaging your credit reports.
Even if you're not using a card, it's wise to sign on and check on it at least once a month to monitor for things like trailing interest (if you previously carried a balance), forgotten AF's and especially unauthorized use!
As far as applying again, I'm not sure how this is going to play out with Chase's internal recordkeeping. They didn't report anything, but they do have their own internal memory... which is loooooooong.