I have a 6 year old EV with very minimal degradation doing all sorts of stuff that is frowned on: charging up to 100% all the time, using fast chargers regularly, and even letting the car sit outside on hot days (it does warn me if it's >100F to get it into the garage).

So no, I'm not really worried as I don't drive a Leaf and my car has industry-standard cooling system for the battery pack.