The way she spoke about the breakup was very honest and respectful and completely understandable. I think it's a situation a lot of people can relate to.
The way she addressed her viewers, not so much. I absolutely agree that influencers don't owe their audience an explanation in instances like this and that it's up to them how much they share. However Emma said she watched last weeks vlog and knew it was obvious that something was wrong. It wouldn't have taken much to add 'please respect my privacy, I'd appreciate it if you could hold off asking any questions' or words to that effect. Instead she addressed that something had happened and that she would talk about it in future, which points out that something has happened to those who might not have realised and might prompt some younger viewers to ask questions. Literally saying 'it's none of your business' to the people who enable her to maintain this lifestyle is bold.