INFO: You still seem to be emotionally hung up on her that you’re demanding information and an apology for not being given information about her relationship, which isn’t exactly a healthy way to be friends with anyone. On the other hand, if you were that close, while she’s not “obliged” to give out information, it is still a realistic expectation.

I’d say confront your own emotions. Did you get back to her for the sole reason of wanting to rekindle the spark OR did things evolve later OR did you genuinely want to be friends only? If it’s the first, then Y-T-A for not asking yourself and being clear. You’re N-T-A for expecting to get back together, but to demand an apology when you didn’t make it clear in any way that this information was something you needed to base your friendship and expectations on is the AH part.

However, if things just evolved on their own, then it’s not your fault or hers, so N-A-H, and if you genuinely just wanna be friends, then you really don’t need that information so being upset that it wasn’t given to you without asking that you demand an apology is AH behavior.