How they never explained how Wolverine regained his adamantium claws in days of future past.
It's a Younger Wolverine and it's the Prequel X-menverse Wolverine as well as Original X-menverse Wolverine in the same Movie
But they did in X-Men: Apocalypse. Look here.
That was set BEFORE The Wolverine.
How about X-Men Origins: Wolverine?
Are you serious?
Obviously, there are inconsistencies between the movies. I guess, you have to make do with what you have available.
What do you think?