I suspect it's followed by a lot of Minbari-level denial and the same thing happening again until S5. Or, possibly:
Lennier spends a long time thinking about it, and Delenn, and prophecies, and trying to work out a way to fit all of this into his universe without it making her not perfect. He ends up deciding that he's messed the ritual up himself by not speaking when he had a ritually-sanctioned time and place to, which would make him dishonest and tarnish the rest of the ritual. (And of course, if he had spoken he'd have hated himself for it just as much, but the idea of it being his fault either way is something he can live with.)
Delenn doesn't talk about it because she doesn't see a reason to, and if she thinks about it at all it's only in the same vague, hazy way she remembers all her moments of doubt regarding who/what she is - it was important at the time, but not any more. The first time she's really confronted with what happened is after reading the journal in OaR, which lists all the rituals he's ever neglected. (It was supposed to be a Ranger exercise in listing your flaws. He was very comprehensive about it.)
After this, she spends a long time imagining other things she could have said and done, and Lennier spends years teaching Religious Caste children; he's never forgiven the Vorlons, and he's afraid that they'll indirectly cause another civil war with the Sinclair/Valen/Valeria/Kosh thing. It doesn't happen, but somewhere along the way he finds his own kind of peace about everything that did.
After SiL he goes to see Delenn, planning to tell her how sorry he is for her loss and how much he's learned since to teach him that he never truly hated Sheridan the way he thought he did, and to teach him that forgiveness isn't something he can expect from some grand gesture for her anyway. He's surprised when she wants to apologise for something that happened so long ago, but by the time he's reassured her it doesn't matter, he's already decided that he's been away from her long enough already.
no subject
Lennier spends a long time thinking about it, and Delenn, and prophecies, and trying to work out a way to fit all of this into his universe without it making her not perfect. He ends up deciding that he's messed the ritual up himself by not speaking when he had a ritually-sanctioned time and place to, which would make him dishonest and tarnish the rest of the ritual. (And of course, if he had spoken he'd have hated himself for it just as much, but the idea of it being his fault either way is something he can live with.)
Delenn doesn't talk about it because she doesn't see a reason to, and if she thinks about it at all it's only in the same vague, hazy way she remembers all her moments of doubt regarding who/what she is - it was important at the time, but not any more. The first time she's really confronted with what happened is after reading the journal in OaR, which lists all the rituals he's ever neglected. (It was supposed to be a Ranger exercise in listing your flaws. He was very comprehensive about it.)
After this, she spends a long time imagining other things she could have said and done, and Lennier spends years teaching Religious Caste children; he's never forgiven the Vorlons, and he's afraid that they'll indirectly cause another civil war with the Sinclair/Valen/Valeria/Kosh thing. It doesn't happen, but somewhere along the way he finds his own kind of peace about everything that did.
After SiL he goes to see Delenn, planning to tell her how sorry he is for her loss and how much he's learned since to teach him that he never truly hated Sheridan the way he thought he did, and to teach him that forgiveness isn't something he can expect from some grand gesture for her anyway. He's surprised when she wants to apologise for something that happened so long ago, but by the time he's reassured her it doesn't matter, he's already decided that he's been away from her long enough already.