What problems are caused by pedagogical blogging about a class?
First, you need to decide the purpose of your blog / your targeted audience.

If you are writing something so your class can be more interactive, you would clearly write it one way (being very careful not to embarrass anyone) - simply removing names might not actually hide identities in a class of 20 students. In this scenario, I don't see a reason to hide your own identity.

If you are writing something for other teachers, to discuss pedagogical issues, then you would write in a very different way. In this case, anonymizing your student names is very important (for different reasons) and you might want to hide your own identity as a way to stop your students or anyone else connecting your writings to a particular group of students.