Lots of articles are saying Ellen "outed" Mariah's pregnancy. This isn't true. Mariah wasn't "forced" to reveal her pregnancy as many are claiming. There was no announcement or press frenzy immediately after this interview. She didn't reveal anything (including her miscarriage) until 2010 when she was pregnant with the twins.
Also, she miscarried before this Ellen interview, not afterwards. Mariah made that clear in the article, but this angle probably makes Ellen look worse.
Don't get me wrong, I think Ellen definitely messed up here. It was intrusive and inappropriate. However, I don't think Ellen considered that Mariah had possibly miscarried. I also don't think Ellen understood how big of a deal revealing a pregnancy is, considering she doesn't have or want kids. It's not on her radar. She has a totally different mindset.
I'm not convinced she meant any harm here. Mariah also went back on Ellen's show several times after this incident. So I think that speaks for itself.