Dont think it needs a new universe but hickman created the perfect vehicle for a reboot. I mean im not an event fan but you just do an event that ends with the death of moira x all of the 616 is rebooted you pick the elements you want to start with like krakoa etc and then the others you just start earlier like a younger cap, younger thor, tony etc. All the previous stuff happened and is still canon but you get sort of a fresh start.