Can the POTUS recent comments on Bergdahl inadvertently set him free?

Perhaps one could have argued Trump's comments during the election cycle might have impacted his trial but he pleaded guilty and admits he did what he has been accused of doing. Trump was also a candidate at the time, not the President. He can have an opinion as a private citizen.

The sentencing process has guidelines a judge can follow based upon a number of factors. A judge needn't consider anyone's opinion in sentencing.

I hope they turn him loose in my backyard if they do- we have hungry alligators and sharks

It shouldn't if the judge is correctly following the orders of the Convening Authority. A simpler example would be getting tagged with a JAGMAN. You do due diligence, stick to the facts, and come to supported conclusions. Yes, the higher ups may push for a predetermined outcome, but that's their improper attempt at tampering. You have to live the rest of your life knowing if you were pure, or not. I once did an Admin that concluded with Command management sponsored sexual harassment (first/second tier management0. It was the realization of the fears of the front office. In the grand scheme of things, the best outcome long term is the right outcome. Politics is fickle. The truth isn't. It just is. Justice on the other hand is subjective. There's a bell curve on opinions on which is the right amount. Whatever is selected, there will be a slice of the bell curve that will be pissed.