English teachers in non-English-speaking countries face the dilemma of which English to teach. Often their school will have a preference for English English or American English, usually based on the textbooks they are using. I remember when I was at university in France one of the lecturers telling me that the way I pronounced 'bath' was wrong because I had a northern accent rather than the 'BBC accent' he wanted his students to learn. Equally, my lecturers back in the UK were a little taken aback when I returned from my year in France with a very strong southern French accent. Given that most people will retain something of a 'foreign' accent when they learn a second language, the most important thing to my mind is to be able to make yourself understood.
My accent has changed since I first came to the United States 25 years ago. It happened partly because as a language teacher I find myself naturally mimicking the accents of those around me. (That sometimes gets me into trouble as people think I'm taking the mickey!) Mostly though it has been a conscious choice to try to change my accent. I got thoroughly fed up of people asking me to repeat myself when I thought I was being perfectly clear. It was just faster and less frustrating to say it the American way. It also didn't hurt to sound more, rather than less, American when I was looking for employment as an English as a Second Language teacher here in the United States. My colleagues occasionally comment on my accent, and on rare occasions I hear my students say something with an English accent (and I then 'correct' them!) One of my colleagues though has a strong accent from the south of the USA, which is just as alien to the northeast as my accent is - and I hear her students picking up her accent!
I suppose schools and universities in some countries may prefer Australian English. I can't think of any that would prefer Scottish English though ;-)