Note that a mistrial keeps Trump off the campaign trail.
As opposed to sentencing that then can start the appeal process.
While you are correct on both counts I am of the opinion that Merchan knows that his legal career is toast if he sentences PDJT to jail. Appeals will overturn Merchan’s trial and he will probably come under legal review and will probably be working traffic tickets in Mexico City this time next year.
The only thing he can do is deflect attention to an outside event that will cause a mistrial to be declared. That way he can claim that he had no option but to release PDJT and wash his hands of the whole affair. To facilitate that Merchan probably paid someone to do the post.
Let Fat Alvin try to get another trial scheduled before the election - good luck with that.