Din Djarin can fully abandon his helmet rules in The Mandalorian season 3 and with good reason. After 16 episodes of the Star Wars live-action series, it appears as if it's finally tackling the original premise that it was sold on. For the first two seasons, the series' focus has been on Baby Yoda and the mystery that surrounds him. Now that he's (likely) taking a back seat, the Disney+ project can properly explore its titular character.
When The Mandalorian was first announced, the general idea was that it would be about the Mandalorians, a long-existing but barely explored group in Star Wars live-action with the titular character being its representative. But it quickly turned into an entirely different series with the arrival of the Force-sensitive creature from the same species as Jedi Master Yoda. Grogu, a.k.a. Baby Yoda's involvement drastically changed the trajectory of The Mandalorian as the focus of the show recentered on him and Din's attempt to reunite Grogu with the Jedi.
Along the way, however, The Mandalorian still attempted to move Mando's personal story forward, albeit slowly. In season 1, a portion of his backstory was explored in flashbacks. Another defining trait of Din Djarin is the fundamentalist Mandalorian helmet code, his strict rule of keeping his armor, specifically his helmet, on at all times — something that's not a universal Mandalorian principle as explained by Bo-Katan Kryze. According to Mando, if he removes it in front of other people, he won't be able to put it on again. Throughout The Mandalorian, however, this principle was challenged and gradually, Din softened up in his stance on the matter. Considering his current situation, however, he could ultimately abandon his strict rules altogether, especially as he potentially becomes the leader of the Mandalorians as the new owner of the Darksaber.
Din first removed his helmet in The Mandalorian season 1 finale out of necessity and only in front of a droid as it needed to be removed to heal Din's injuries. By the time The Mandalorian season 2 rolled around, however, Din was more willing to bend his rules, as cleverly pointed out by Bill Burr's Mayfeld in episode "The Believer." The last two times he removed it indicated Din's loyalty to the code had now been replaced by his loyalty to Grogu, the Child now being his greater purpose.
Din's evolving stance on wearing his helmet could be traced to his initial encounter with Bo-Katan in Trask. Confident in his Mandalorian dogma, he chastised her for willingly showing her face, coming to the conclusion that she and her Nite Owls weren't real Mandalorians. But she snarkily retorted that Din is actually the one who's not a proper Mandalorian; being a Child of the Watch makes him a part of a “cult of religious zealots” who wished to return the Mandalorians back to their ancient ways. If Din takes on the responsibility of being the leader of Mandalore and attempts to unite his people, it won't help his cause if he subscribes to an outdated code. His affiliations with a cultist offshoot group could not only make his possible new mission more difficult, it could ultimately make it impossible to accomplish.
Bo-Katan is arguably better positioned to be the figurehead of the Mandalorians, being the sister of Duchess Satine Kryze, but even she struggled with establishing her leadership. It's safe to imagine that Din Djarin, who doesn't have the same name recognition, will have a more difficult time with this task. Since Bo-Katan had been pinning her hopes on winning the Darksaber to establish her as the rightful Mandalorian leader, she might even use Mando's history as a Child of the Watch to discredit him. Given this, Din should prove himself worthy of the position and appeal to as many Mandalorians as possible which would justify him renouncing his helmet rules come The Mandalorian season 3.
