Yes, I think so. I have a classmate and she had been staying in London for 15 years. When we talked via Video call, I realized that she develop an British Accent. There are also some people who have been staying in different country and they develop the accent. I think they been on that country for so long that they are used to the accent or the intonation on how to speak it. If they continue to speak their original language or dialect, for sure they will remember on how to speak both of the language. Some really are into the new language or their second language they know the language by heart and it is sounded really that way. I think it depends on how you needed to learn the new language and how many times you have to use it that you develop an accent.