Tbh I always assumed Bonnie never opened the letter bc Caroline told her what was in Alaric's letter and she assumed they said the same thing. And so she thought Damon hated her bc she was 'not Elena'.
I also thought about this, actually! Like if Bonnie were to ever have discussed it with anyone, it would’ve been Ric/Caroline over Stefan no question. And the version of events Ric got has been disproven like 5 separate times narratively so far, so I’m more and more convinced that rather than DE fanservice, it was actually just introducing us to Bonnie’s perspective in that coffin scene. Like it was meant to prep us for her take on things, because otherwise she would’ve had to spell it out in the scene and the dialogue would’ve gotten clunky for such an intense goodbye (and also her keeping her language vague kept Damon from openly refuting it). So yeah, I don’t know if she ever explicitly asked (or that she’d need to have heard what was in Ric’s letter to assume what his reasons were since we already saw her do that in their non-goodbye) but I think it’s a really strong possibility/theory. It doesn’t make sense for her to have talked about it with anyone else.
