Obi-Wan went over thirty years without a heat. It was hardly unusual or unexpected. Everyone knew omega reproductive systems were finicky. Omegas were incredibly fertile while in heat. Nature had, perhaps, compensated for the situation by ensuring they only went into heat when...conditions were correct. OR, the Dark Side AU where the Empire is already in power, the Jedi are long gone, and Obi-Wan Kenobi ends up leading an army to wipe out the Emperor's enemies. Things get more complicated when he goes into heat.

They were made for the Jedi. That’s the party line, anyway, and Rex says, “Yes, sir” because he was trained by the best, but he doesn’t believe it. And then Knight Kenobi becomes part of the 501st. He wears beskar’gam and headbutts droids and one time he confesses that the last time he fought in a war, he had to leave the Order to do it. Rex still doesn’t believe that he and his brothers were made for the Jedi, but he thinks maybe, this Jedi was made for them. Or, the one where Torrent is Like That, and Cody blames them for all his premature gray hairs.

Two months after the Guard officially moves to Coruscant, the lawyer shows up. _ In which Obi-Wan Kenobi never returns to the Jedi order after the war on Melidaa/Dann and instead finds another way to follow the Force's will. Namely, by fighting sentient-rights abuses all over the galaxy and emancipating the Grand Army of the Republic, one clone trooper at a time.

“You have a choice,” Cody begins. “I don’t want any of you to think that you don’t. If you want no part of this, all you have to do is say so. But if I know any of you half as well as I think I do, this choice won’t be particularly hard to make.” He takes a deep breath and counts his heartbeats against the reverent silence of the mess hall. “We may belong to the Republic, but we were made for the Jetti.” And thus, the 212th Attack Battalion abducts their General. (It's for his own health, really.)