Hugh Jackman was part of the ot cast, when people mention the ot cast, he's included in that cast and Hugh himself called themselves as the "originals". That being said, none of the Wolverine solo films have outgrossed X3 in North America and the highest grossing film in the series is dofp which featured the return of the original cast together.
And Hugh Jackman was in Apocalypse btw.
Personally speaking, I wanted a X5 with the Wolverine. As for McAvoy, Fassbender, Lawrence, they don't bring much attention to the series. First Class didn't open big and was considered an underperformer at the boX office.Apocalypse could have opened bigger despite the bad reviews. Movies like Aladdin, Origins Wolverine, Fifty Shades, Suicide Squad, BvS, TMNT 2014, Twilight Saga and the Transformers movies didn't a fresh rt rating for people to make them a success, so why should that be the case for Apocalypse and Dark PhoeniX, Xpecially Apocalypse, a sequel to Dofp. There isn't just enough public interest to the First Class cast.