The site reports that the villains will be the cyborgs known as The Reavers. While we know that Boyd Holbrook and Richard E. Grant are expected to be antagonists, they are of the scientist variety and may or may not be part of the group, although there's the suggestion Grant could be playing their leader, Donald Pierce. In the comics, Pierce is a member of the evil cabal known as the Hellfire Club, a group we saw in X-Men: First Class led by Kevin Bacon's Sebastian Shaw. They could return as the major force backing the Reavers, or it could be the group teased during the X-Men: Apocalypse closing credits. I'll leave that one secret for those who haven't seen the film yet. Nerdist also claims to have heard "small rumblings" that Liev Schreiber is returning as Sabretooth. "Small rumblings" probably means a bunch of geeks sitting around the water cooler hoping he comes back.
The Reavers were major X-Men foes during the team's stint headquartered in Australia. Along with Pierce their members include Skullbuster, Lady Deathstrike (played by Kelly Hu in X-2), Bonebreaker, and others. Their shining moment came in issue #251 when they defeated Wolverine and crucified him on a giant X. It's a memory that haunts Wolverine for years afterwards.
Take all of this with a heaping spoonful of salt, of course. Wolverine 3 will be directed by James Mangold and opens March 3rd 2017.