Do you feel like the X-Men series will end after Hugh Jackman retires as Wolverine, or will they just find a replacement/kill the character?
Actors get replaced all the time. They'd just reboot it. Look how many Bond actors alone there are.
It'll continue and, most likely, Tom Hardy (Mad Max) will replace him. That's if they listen to Jackman request/suggestion.
I think it'll continue. Hollywood likes to shake the money maker as long as possible.