The trouble is that we don't really know what it would take to stop him, since there is no blueprint. We could perhaps say give his fight history, that a cuts based stoppage might happen in certain circumstances.
I think that your list is about right, though I might add Liston. I would then make my prediction as unspecific as possible.
I'll add Liston. Vitali Klitschko might turn the trick, he isn't as big a hiitter as his brother, but he is more adventurous and willing to trade ,I doubt Marciano could land much from the distance Vitali keeps his opponents. Emmanuel Steward said Rocky would be too small to beat modern super heavies.
He has a decent chance yes.:good Its possible a Tua ,Ibeabuchi or Frazier might turn the trick and "out Rocky, Rocky," but I would be inclined to doubt it.
They always say cuts! The second Charles fight in Sept. 1954 saw the former champ split Marciano's nose open down to the bone!!! The doctor and the ref gave The Rock 1 more round...he stormed out...KO'd Charles...and kept the title. Been watching boxing for 50 years...I've seen guys quit on their stools for a LOT less! Marciano had a knack of coming up with the big punch when he had too...lots of fighters didn't have that ability. To beat him...you'd have to kill him. His heart and will to win were just too big...in my opinion.
It would take a guy bigger than him. It could and would happen against the REALLY big guys, like Ali or Holmes, somebody with the size AND skill. Lewis or Wlad maybe too, just because they were going to keep him on the end of their fighting radius and clinch like crazy if he got in close. Just too much size. At some point, one has to acquiesce that even though Marciano was great, a great fighter with overwhelmingly superior height and weight will simply have too much for him to overcome. He wasn't superman.
I dont think Holmes could handle Marciano's right had and finishing ability and Ali would also have problems with the pressure and awkward power shots (the Bonavena fight showed this and Marciano was better in every area than Oscar) I think it would have to be the bigger guys like Lennox or Vlad Vitali or Foremen but all of these men have also been stopped or injured by lesser punchers so I would never count Marciano out.
I'd add Wlad to the OP's list and strike Dempsey. There's actually a few of the more modern super heavies I can see getting the job done. Bowe and Tua perhaps the ones that springs first to mind. For his time, Marciano had first rate power, strength and chin. But being a 185 lbs come forward fighter against bangers around 230-250 lbs...