Are the air bubbles that exit the anus during prostration—which Dr. Muhammad Hammouda describes as real gases—considered among the nullifiers of ablution, and should attention be paid to them, or are they considered whispers from Satan as Sheikh Muhammad Al-Arifi mentioned?

The rule is not to pay attention to doubt and whispers (waswas). So, if you doubt the emission of wind and do not reach a level of certainty, then act upon the original state, which is the persistence of purity, and do not indulge in the whispers. The statement of the mentioned doctor is to be understood as referring to someone who is certain of the emission of wind, whereas the statement of the Sheikh is for the one afflicted by whispers. Thus, there is no contradiction between them. You must ignore these whispers.