does he have to face either the winner of wilder-helenius or ruiz-ortiz before he can do the unifcation with usyk?
Short answer: No. Longer answer: Fury just fought his mandatory Whyte in April. There is no WBC mandatory currently. The WBC is holding an eliminator between Ruiz and Ortiz next week, but it hasn't been called a "final" eliminator. So the winner of that one will likely have to fight someone else first to become the mandatory. Fury just has to fight once a year. So, technically, he doesn't even have to get in the ring until next April. If he signs for a unification, the WBC will be all for it. It will give them more time to find a new mandatory. And they'll get an extra-large sanctioning fee for Fury-Usyk. The guy with the mandatories is Usyk. The WBA is first up. Followed by the IBF and then the WBO. So Usyk has to fight that org's mandatory. But it isn't clear who that is. Since Helenius won a WBA eliminator in his last fight, will Helenius-Wilder be the WBA final eliminator? Daniel Dubois and Dillian Whyte are actually negotiating. Would the winner of that fight be the mandatory? Hrgovic just won his IBF mandatory. So he's the next mandatory after the WBA sorts itself out. (Although Hrgovic is willing to rematch Zhang first.) The WBO mandatory will be determined, I believe, by Joyce-Parker. The winner of that fight is third in line (after the WBA mando and Hrgovic). So there is time really for Fury and Usyk to fight ... unless the WBA decides to get weird and force something (or the IBF and WBO try to jump ahead and force a defense). But I think the WBC is fine with Fury fighting Usyk next. I heard Warren already sent the WBC a letter saying Fury will defend their title. So they should be fine with whoever that may be until April next year. That's how it stands right now. But these things are always fluid.
Actually, Usyk publicly stating he won't fight anyone next except Fury might cause trouble within the WBA, WBO or IBF. They all get a little "offended" when they don't feel "in charge." For all Fury's talk and people getting mad at him for saying this and that, Usyk saying he isn't going to fight anyone else might actually be the comment that causes more problems - if someone at one the orgs gets a wild hair up their ass. Because Usyk has been a champion for a year and he hasn't fought a mandatory yet. The rematch with Joshua didn't fulfill any mandatory obligation for Usyk. None of the orgs rated Joshua as their mandatory. And the last WBA mandatory fight was FOUR years ago (Joshua-Povetkin). Fury fought his mando a few months ago.