[dbt00]

If you believe that Trump works under mafia rules of intimidation and plausible deniability, then you can read this as Assange can support Trump's theory that the emails came from the Ukraine, or he can face prosecution.

It's unlikely that someone with such an understanding (whether or not it's a correct assumption) would believe that Assange coming forward and saying he was given the emails by Russian assets coordinating with Roger Stone under the direction of Trump would then result in the promised pardon.

Note that, since then, Assange has not come forward with exculpatory evidence for Trump and the administration has begun prosecuting Assange.