There would have been an undisputed champ, because of the HBO unification tourney that was going on. So, Berbick vs Smith for the WBA/WBC belts, with the winner to face IBF champion Tucker, and presumably the winner of all that to face Spinks and probably a comebacking Holmes as well. It's a tricky call, but I think Tucker comes out of that group as top dog. How long he lasts is another matter, since he'd still have the same managerial and personal problems. No one contender in this era was markedly better/more consistent than the others, so we'd probably see the title being passed around a lot.
Until about 1988 when Evander Holyfield enters the scene as a full-fledged heavyweight. You would remain unchallenged until Rid**** Bowe and or Lennox Lewis are able to challenge him. The result of these fights would be the subject of undoubtably endless threads of their own.
Who did Tucker face of any significance before his come back post Tyson? Perhaps you would have been treated differently by Don King.
I also wonder how long it would have been before the alphabet organizations stripped the champion in order to line their own pockets.
I think it is likely that we never would have seen Douglas in his career best performance absent the alignment of the stars that we saw in Tokyo.
Another question is, would Holyfield have beaten Tyson's reign? I believe he beats them all including Douglas. He might not win some as emphatically as Mike but he'd win them nethertheless. He also beats Douglas in style before meeting Bowe.
Michael Spinks would have probably won the unification tournament, around mid-'1987. Then lost to Holyfield soon after. Tucker might have got a shot at Holyfield, but he'd lose. Holyfield dominates.
there was never a bigger dragon to slay than Tyson thats for sure. without Tyson the division would have been close to dead at that time until the early 90s.
No fighter was good enough to win and hold the championship during that time. So the title whether the paper championship or the true championship is passed around until Tyson.