Marvel owns the rights to the x-men universe which includes its wide span of stories and characters, further more, they cermented that right when they made wolverine a icon figure from the movie franchise closely linking stories featuring wolverine, that hadnt been taken by other studios...
so for example where Alpha Flight, Silver Samuri... X23 - any story featuring them which previously hadnt been taken by any other studio
Where as any story featuring Hulk, Ironman blah blah blah...
So essentially the answer to you question is Fox owns Alpha Flight...
However there is an exception to the rule...
Although Fox has the monopoly over the characters, they can still return the rights to Alpha Flight if say they wernt going to persue its creation.
But that would be something along the lines of
Studio 1 (Marvel Studios or Sony or Universal) Studio 2 (Fox)
Studio 1 "Can we have the rights to Alpha Flight to make it into the movie?"
Studio 2 "Well, we love Hugh Jackman"
Studio 1 "(Arkward Silence)...OK, but basically we have this idea to mave a canadian superhero team, which could potentially be something new... There canadian"
Studio 2 "So is Wolverine, doesnt he have beautifle eyes..."
Studio 1 "Look we know that Alpha Flight has had some involvement with Wolverine..."
Studio 2 "OoOo you said Wolverine"
Studio 1 "We're willing to give you say this brief case full of money, for the rights to use this franchise"
And this is the point where you have too scenarios...
Scenario 1
A few Fox members gather in a huddle acting way to sinister
Studio 2 (Larry) "Well, Wolverine is erh, erh, erh is going on vacation"
Studio 2 (Dave) "After Japan of course"
Studio 2 (Larry) "Yes, in Wolverine 3 wolverine is going to have a vacantion"
Studio 2 (Dave) "In Canada"
Studio 2 (Larry) "Yes in canada,and well we need him fighting in a bar at the end of it so Of Course wolverine is going to run into Alpha Flight"
Studio 2 (Dave) "Naturally"
Studio 2 (Larry) "So no, you cant have the rights because basically we could make lots more money making alpha flight so i can spend that money with spa breaks with Hugh Jacman, so we may want to make a wolverine movie in the future"
Studio 2 (Dave) "Alpha Flight Movie"
Studio 2 (Larry) "Sorry yes i mean Alpha Flight Movie"
Studio 2 (Dave) "Oooo staring Wolverine!"
Studio 2 (Larry) "Yes, we will call it, Wolverine and The Alpha Flight"
Studio 2 (Dave) "Thats quiet a long title"
Studio 2 (Larry) "What do you suggest?"
Studio 2 (Dave) "I dunno, Wolverine...and...erh The Other guys?"
Studio 2 (Larry) "Perfect, so Studio 1, unfortuatlly"
Studio 2 (Dave) "They left five minutes ago..."
Scenario 2 could be this...
Studio 2 "Is that a Million?"
Studio 1 "You want 2?"
Studio 2 "Lets round it up to ten and we have a deal"
Producer for Studio 1 "Isnt that the entire budget for alpha flight"
Studio 1 "Shhhhh, we will film it on a sony handycam and say its a revoltuionary new filming techique like Cloverfield..."