Why would the likelihood go up under his model? If Musk had only offered $35 and people thought that was only 20% likely to happen (for the reasons you listed) then the market price would have only gone up to $31.
Say I offer to buy Apple for a penny/share. The price for their shares won’t move because of my offer but may move from normal market conditions. If the shares increased a dollar the day after my offer, would you say there’s a greater than 100% chance of my offer being accepted?
There of course the implicit assumption here that Musk's offer is causally related to Twitter's stock price. OPs comment make sense if you keep that in mind.